The Eye
From Primary Surgery
The general method for the eye
There are 30 million blind people in the world. Half of them are blind from cataracts, and a quarter from trachoma. The other major causes of blindness are glaucoma, vitamin A deficiency, corneal infections, and onchocerciasis. In the industrial world two people in a thousand are blind, but in the developing world blindness is ten times more common-one or two in every hundred. Cataract can be treated, and glaucoma can be arrested; trachoma and vitamin A deficiency can be prevented. It is unfortunate therefore that ophthalmology scares most doctors, who imagine that the eye must be impossibly difficult. This is not true: you can diagnose 90% of eye diseases with a torch and an ophthalmoscope.
Someone in the district must be able to do cataracts and trabeculectomies. Surgery inside the eye is difficult, so learn these operations by apprenticeship from an expert; they are not described here. They can also be done by a medical assistant. Here is the basic eye equipment-it does not include equipment for operating inside the eye. Look after it with the greatest care.
• CHARTS, visual acuity, (a) Snellen and (b) illiterate E charts, both for use at 6 metres; one chart only of each. These are essential, and can usually be produced locally. They have patterns of 'Es' of different sizes in different positions, and can be used by patients who cannot read.
• TEST TYPE, reading pattern, one set only. Optional. Use this for examining older patients with presbyopia who need glasses. If necessary, you can also use a book or newspaper.
• TORCH, for focal illumination, local pattern, preferably pencil type, with 'lens bulb: one only. A locally available torch is adequate: it can be easily replaced, as can its bulb and batteries.
• LOUPE (magnifying spectacles), binocular, surgical, Bishop Harman headband type, x2- xB, one only. Some simple form of magnification is useful for examining the front of the eye, for removing superficial foreign bodies, and for other kinds of fine work, such as suturing nerves.
• TONOMETER, SchitJtz, one only. You must be able to measure the intraocular pressure (lOP) if you are going to diagnose glaucoma. Digital measurement is simple but unreliable, unless the pressure is very high (>40 mmHg), by which time there may be advanced loss of vision.
• OPHTHALMOSCOPE, simple pattern, Keeler type, battery handle, one only. An ophthalmoscope is very useful, but you can do much good eye work without one.
• SLIT LAMP MICROSCOPE, on stand, simple pattern, as Inami 911SX or equivalent, one only, optional. You will find a slit lamp useful, although you can diagnose uveitis without one. Read the pamphlet with the instrument, and spend some time with an experienced operator.
• NEEDLES, retrobulbar, 7 cm, blunt tip, very fine, one box only. These are the best needles for retrobulbar blocks, but you can use any long thin needle.
• SPECULUM, ophthalmic, lid, solid blades, hinged with screwadjustment, one only. You can only insert a lid speculum after a patient has been anaesthetized with drops of a local anaesthetic.
• SCISSORS, ophthalmic, lid, blunt points, one only. If necessary, you can use any fine scissors.
• FORCEPS (clamp), tarsal cyst (chalazion), Bmm ring, Lambert pattern, one only. This has two blades, one with a ring and the other with a plate. Use it to hold an eyelid while you incise a tarsal cyst.
• CURETTE, chalazion (tarsal cyst), one only.
• CAUTERY, simple type, ball pattern, two only. Heat this on a spirit lamp.
• CLAMP, eyelid, entropion, Desmarre's or Snellen's, (a) medium and (b)large, one only of each. Use this to hold a patient's eyelid when you operate for entropion.
• SCISSORS, ophthalmic, spring pattern, Westcott's or Castroviejo's, two only. These are particularly delicate instruments which need treating with special care.
• FORCEPS, fine, toothed, St Martin's, two only.
• RETRACTOR, eye, Desmarre's, one only. Use this for examining children.
• NEEDLE HOLDER, ophthalmic, curved with lock, Castroviejo pattern, (a) light, (b) heavy, one only of each type. Use the light pair for suturing a corneal laceration, and the heavier pair for lid surgery.
• TRIAL LENSES, basic set with trial frame, spherical lenses only, cylindrical lenses not reqUired, one outfit only. These are for prescribing glasses to correct refractive errors, and are a luxury unless spectacles are easily available.
• GLASSES, simple frames, second-hand if necessary, spherical lenses + 1 to +3.50-the most commonly needed glasses are +2 and +2.50, several hundred assorted. If you can stock glasses you can deal simply and effectively with the reading difficulties of most patients.
• BASIC DRUGS. Antibiotics. Topical antibiotic: enriched tetracycline (or chloramphenicol) eye ointment 10/0. Subconjunctival antibiotic: Gentamicin injection 40 mg/ml. Drugs acting on the pupil. For diagnosis: cyclopentolate 1% or phenylephrine 10% For treatment: atropine 1% as ointment. Pilocarpine 4% for glaucoma. Local anaesthetics. Lignocaine hydrochloride 4% or amethocaine hydrochloride 0.5% Steroids. Hydrocortisone 1% (a weak formulation). Vitamins. Vitamin A capsules 200,000 iu. Diagnostic materials. Fluorescein papers.
Sandford Smith J, 'Eye Diseases in Hot Climates', John Wright.
Schwab L, 'Primary Eye Care in Developing Nations', Oxford University Press
Galbraith JEK, 'Basic Eye Surgery, a Manual for Surgeons in Developing Countries', Churchill Livingstone, 1979
Parr J, 'Introduction to Ophthalmology', Oxford University Press, (2nd edn 1982)
THE GENERAL METHOD FOR an eye
HISTORY Always take the patient's history carefully, it may be critically important. Occasionally it is misleading. He is likely to have: (1) An acute red painful eye(s), which has occurred spontaneously (24.3), or is the result of trauma (Chapter 60). (2) Gradual or sudden impairment of vision in one or both of his eyes (24.5). (3) Gradual difficulty reading, usually in patients over 40 (presbyopia, 24.8). (4) Other less common but often important eye symptoms, such as squints (24.9), protrusion of the eye (proptosis, 24.11), or difficulty opening his eye (ptosis, 24.15) or closing it (Iagophthalmos, 30.3).
If he has pain, try to distinguish: (1) The deep pain caused by an abrupt increase in intraocular pressure. (2) Foreign-body pain from irritation of his conjunctiva. (3) Superficial pain in an eyelid. (4) Photophobia, which is eye pain on exposure to light. (5) Minor discomforts which may result from inadequately corrected refractive errors. (6) Headaches.
EXAMINING AN EYE The standard examination of an eye is time-consuming to do well, so train a nurse or medical assistant to test a patient's visual acuity and examine his eyes. At first he will refer many patients to you. Later, he will be able to see 90% of the patients himself. Your consulting room must be at least 6 metres long and you should be able to darken it. You must have a good light. Most examinations can be done while a patient sits in front of you.
MEASURING HIS VISUAL ACUITY. ALWAYS test his visual acuity. Explain to him that you want to test his eyes. Begin by testing them separately (with distance glasses if he wears them); test them again each time you see him; and record your results, so that you will know if his vision is deteriorating or not. If he can read, test each eye separately with Snellen's type.
Stand him 6 metres from the well-lit chart, and close his left eye with a piece of paper or your left hand. Ask him to start at the top and tell you whether the "three legs go up, down, right, or1eft", until he cannot read any more. The top figure is the distance in metres to the test chart, the bottom one is the distance at which a person with normal vision can read that line. The usual sequence of tests getting progressively worse is: 6/6, 6/9, 6/18, 6/60,3/60. CF 3 m (count fingers at 3 metres) is equivalent to 3/60. If he cannot CF at 1 m, try hand movements (H M), and then test for the perception of light (PL). If you shine a torch into each of the 4 quadrants of his visual field, can he tell you where it is coming from?
Visual acuity can be usefully divided into four groups: (1)Good vision 6/6-6/18; (2) poor vision 6/24-6/60; (3) blind CF 5 m-PL (he can count fingers at 5 metres to perceive light); (4) blind to light NPL (he cannot perceive light). Blindness is a loss of vision which results in the patient being unable to continue with his normal life, and to walk unassisted'. It is usually equivalent to binocular vision of <3/60, which is the same as <CF 3 m. Before you decide that he is completely blind, test him with a very strong light. If an eye cannot see any light, and its pupil does not react to light, it is sure to be beyond help, so there is no point in referring him. If his vision is normal and remains normal and his eye is white, referral is rarely necessary.
EXAMINING THE OUTER EYE WITH A TORCH Start by looking at his face. Note any abnormalities of his lids, lacrimal apparatus, puncta and canaliculi, his lacrimal glands and sacs, and also any epiphora (tearing). If he is in much pain, and his eyelids are in spasm, one drop of a sterile local anaesthetic will make examination easier.
Do his eyelids open and close normally? You can see this best when he blinks. Check his lids for swellings, and check that his lashes are in their normal position.
Are his conjunctivae white? Note particularly the distribution of any redness. If it is maximal near his corneoscleral junction, it is ciliary hyperaemia (this occurs in iritis and corneal ulcer). If it is maximal at the periphery but often extending all over, it is likely to be conjunctivitis. To examine the conjunctiva of his upper lid, evert it as in H to K, Fig. 24-5.
Look for pus or mucopus in his inferior fornix. This is present in all cases of bacterial conjunctivitis, and in some cases of viral conjunctivitis. Look also for signs of vitamin A deficiency: dry-looking conjunctivae, or Bitot's spots (white patches on the temporal side of his conjunctiva).
Are his corneae bright, shining and clear? Surface irregular? (corneal ulcer). Pannus superiorly? (trachoma, 24.13). Haziness? (oedema from trauma, keratitis, or glaucoma).
Is the surface of his cornea normal? Ulcerated? Instil one drop of 2% fluorescein, or dip the end of a fluorescein impregnated filter paper inside his lower lid for a few seconds. Mop out the excess fluorescein with tissue paper. Shine a light on his eye at an angle. Gaps in the corneal epithelium stain green (foreign bodies, ulcers, abrasions).
Is his anterior chamber normal? Note its depth. Is there any blood (hyphaema, 60-7), or pus (hypopyon, Fig. 24-7) on the bottom of his anterior chamber?
Are his pupils black? Do they react to light? Pupils grey or white? (opacities in the lens, cataract). Note their size and shape. Is their outline irregular? (adhesions of his iris to his lens, called synechiae, due to iritis). A pupil which is large and does not react to light in an eye that cannot see? (most likely optic nerve damage, commonly caused by glaucoma).
SPECIAL EXAMINATION METHODS FOR THE EYE THE PIN-HOLE TEST is a useful way of screening for refractive errors. If he has poor vision, place a card with a 1mm hole (punched with a pencil) in front of his eye. If he has an uncorrected refractive error, his vision will be improved. If he has a lesion of his retina or optic nerve, it will be worse.
DIGITAL TONOMETRY to measure the intraocular pressure (lOP). Ask him to look down and keep looking down, but not to actively close his eyes. Put the tips of both your index fingers on one of his globes, so as to feel his sclera through his upper lid above the upper border of his tarsal plate. Gently press with alternate finger tips towards the centre of his globe: (1) Gently fluctuate it from one finger to another. (2) Indent it with one finger and estimate the sense of fluctuation imparted to your stationary finger. (3) Estimate the indentation of his sclera as you relax your indenting finger. You can judge his eye to be 'soft' « 10 mmHg), 'normal (10-35 mmHg), or 'hard' (>35 mmHg). This is a crude test, and he must have a significant rise of pressure (> 30 mm Hg) before you can detect it.
SCHIOTZ TONOMETRY Clean the instrument with a pipe cleaner and ether. Using the standard 5.5 gram weight and the metal footpad, make sure the instrument is calibrated to zero. Explain what you are going to do, lie him flat and instil a local anaesthetic into his conjunctiva. Ask him to open both his eyes, and look straight up at a target placed on the ceiling.
With the 5.5 g weight in place, put the tonometer plunger gently on the centre of his cornea with his eye open, and read the scale. If in doubt, repeat the reading 3 times. Use the tables provided with the instrument to calculate his lOP from the scale reading.
The normal lOP is 7 to 25 mm Hg. In practice, using the 5.5 g weight, a scale reading of 2 or less (>28 mmHg) indicates a raised IOP. A reading of 3 or above «25 mmHg) is 'normal'. If his lOP is >40 mmHg, his cornea is likely to become oedematous (the characteristic 'hazy cornea' of glaucoma), and you can see this with a torch. This is usually a late sign of glaucoma.
OPHTHALMOSCOPY to examine the fundus and media of a patient's eye. You must, either, dilate his pupils with a short acting mydriatic such as cyclopentolate 1%, or examine him in a dark room. (1) Ask him to keep both eyes open and look straight ahead. (2) Start with the '0' lens in the ophthalmoscope (unless you have a refractive error and are not wearing glasses; if so select the appropriate correcting lens and use this as '0'). (3) Use your right hand for his right eye and your left hand for his left eye. (4) Hold the sight hole of the ophthalmoscope close to your eye, resting it against your nose and orbit, and move it with you as if it was attached to your head. To find this position, look through the sight hole at some distant object. (5) With your thumb on his forehead gently raise his upper lid clear of his pupil. (6) Start with the ophthalmoscope 20 cm from his eye, and shine the light into his pupil; it should glow uniformly red (the red reflex). (7) Move closer and watch for any opacities in his media silhouetted against his red reflex. If you see a shadow, use the + lenses (+ 5 to + 12) to see it more clearly. (8) Ask him to look straight ahead, and move as close as you can to his eye without touching his eyelashes or cornea. (9) Find and look at his optic disc: it is 15° to the nasal side of the optical axis of his eye. (10) Turn the wheel with your forefinger to get the best view of his disc. Examine: (a) The vertical cup/disc ratio (a ratio of > Y2 suggests glaucoma, 24.6). (b) His disc margins; if these are blurred all round (360°) it suggests papilloedema (refer him). (c) His blood vessels, looking for haemorrhages and exudates suggestive of diabetic retinopathy. (d) His macula, for black and white pigmentation which may suggest choroiditis involving his macula (macu lopathy).
SLIT LAMP MICROSCOPY. Position his head by placing his forehead and chin on the rest. Vary the angle of the light as convenient. Examine his eye layer by layer: conjunctiva- cornea- anterior chamber-lens.
Conjunctiva: Foreign body? Cornea: Foreign body embedded in his cornea? Ulcer? Note its size and shape after instilling fluorescein and using the blue light. On the back of the cornea look for keratic precipitates (KP, these are clumps of white cells, and indicate uveitis). Anterior chamber: look for cells and flare, pus and blood; estimate its depth. Lens: Posterior synechiae from his iris? Opacities? Vitreous: Particles from a recent posterior uveitis, or bleeding?
MOVEMENTS. Test the movements of both his eyes together, and then test each eye separately, in all directions, including convergence. Note any squint (24.9).
DIAGNOSIS. You have now examined his eyes and should be able to make a provisional diagnosis.
BASIC METHODS FOR the eye
BASIC DRUGS, Here is a list: Antibiotics: Tetracycline or chloramphenicol eye ointment, and eye drops. Ask your pharmacy to make up eye drops in used injection bottles and autoclave them. A little gentamicin for subconjunctival injections will go a long way. Don't use penicillin locally on the eye, either as drops or as subconjunctival injections; it does not keep well and may cause hypersensitivity, especially in light-skinned people. You can get high concentrations of an antibiotic inside his eye by: (1) Injecting it subconjunctivally (see below). (2) Applying it frequently (not less than 4-hourly) as drops into his conjunctiva. If an eye infection is severe, give him systemic antibiotics also. Systemic chloramphenicol will enter his eye.
Drugs acting on the pupil: You will need mydriatics to dilate it. Atropine 1% as ointment or drops will dilate his pupil for a week, so only use this for treating iridocyclitis. Cyclopentolate 1%, or phenylephrine 10%, will dilate it for some hours only, so use these when you want to examine him with an ophthalmoscope.
Steroids may be indicated in iridocyclitis. They quieten the inflammation, reduce photophobia and lachrymation, and make the eye white. Use hydrocortisone or prednisolone as a 1% suspension. The frequency of administration depends on the degree of inflammation; you may have to administer them every 3 hours night and day.
CAUTION! (1) Steroids can cause viral and fungal corneal ulceration, glaucoma, and cataracts. They are dangerous in the hands of the nonexpert, so prescribe them with the greatest care. (2) Don't use any steroid unless you are certain about the diagnosis, and then use the weakest commonly available one; which is hydrocortisone 1%. (3) Avoid more powerful steroids, such as dexamethasone, because they are more likely to induce glaucoma in a susceptible eye. See also Section 24.5.
Local anaesthetics: Lignocaine hydrochloride 4% or amethocaine hydrochloride 1% (A 5.8).
CAUTION! The great danger of an anaesthetized eye is that a foreign body may get into it, of which he is unaware, or that he may abrade it, so shield it.
Diagnostic materials: FI uorescein papers are better than fluorescein drops, because you can more easily keep them sterile.
Placebo: If he wants something for his eyes and you need a placebo, give him saline eye drops 0.5%.
EYE DROPS. Pull his lower lid down so that you can see his conjunctiva. Ask him to look up. Put drops or ointment into the outer third of his conjunctiva. Close his eye for two minutes to allow the drug to enter his eye. Don't let the dropper touch his eye, or it may become contaminated. If possible, each patient should have his own drops, because of the danger of cross infection.
TO MAKE CHLORAMPHENICOL EYE DROPS dissolve two 250 mg capsules in 100 ml of water. Filter the solution into sterile 10 ml dropper bottles. Screw the caps on loosely, and sterilize them in a hot water bath at 100°C for 30 minutes, without letting the water splash over the necks of the bottles. Refrigerate them; their shelf-life is 2 months at 2-8°C. The shelf life of commercial drops is only 4 months, so this is a useful method.
SUBCONJUNCTIVAL ANTIBIOTICS are indicated if he has a severe corneal infection or ulceration, especially with hypopyon. You can inject a volume of 0.5 ml (max 1.0 ml) under his conjunctiva. If this contains 0.2 ml of a local anaesthetic, such as 2% lignocaine, the injection will be almost painless. Use a sharp 0.4 mm needle on a 2 mr syringe, as in E, Fig. 24-5.
CAUTION! Be careful which antibiotics you mix in the same syringe. Don't mix crystalline penicillin and lignocaine. Gentamicin alone is not too painful. Anaesthetize his eye with a few drops of local anaesthetic solution. Ask him to look up. Pull down his lower lid, with your finger on his cheek. Rest the needle flat on the conjunctival surface of his globe, with the bevel facing away from it. Push the, needle under his conjunctiva, parallel to the surface of his globe, rotating it gently as you do so. If it is in the right layer, you will see its point under his conjunctiva. Then inject.
Inject gentamicin 40 mg (the standard antibiotic forthis purpose), or chloramphenicol 100 mg, or soframycin 50 mg, or methicillin 100 mg, or ampicillin 100 mg. Make these up in a volume of 1 ml. Don't use penicillin, because of the danger of hypersensitivity. Systemic chloramphenicol enters the eye; so if his eye is severely infected, give him 500 mg 4 times a day for 10 days.
If his infection is getting worse, repeat the injection, daily, for 2 or 3 days (3 is the maximum) until you are quite sure that there is going to be no endophthalmitis. A severely infected eye is is likely to improve, or be lost, in a few hours, so subconjunctival injection is usually only done once, or occasionally twice, on successive days.
WARM SOAKS are an old method, but are an effective one for soothing a painful eye. Ask him to wrap a cloth round a spoon, to dip this into very hot water, and to hold it as close to his eye as he can bear. Soaks are useful for a stye (infected eyelash follicle).
PAD HIS EYE if he has had a minor injury with no suspicion of perforation (60.4). An eye pad, with gentle firm pressure, will reduce his discomfort, and promote healing by preventing his lids moving over the injured area.
Shut his eye, put a pad of gauze over it; place two pieces of adhesive strapping diagonally across the pad, from his forehead to his cheek, to hold the pad in place. Change the pad daily, and look for signs of ulceration or infection.
CAUTION! The great danger of an eye pad is that it may rub against an anaesthetized eye, and cause an abrasion. So his eye must be shut when you apply the pad. A layer of vaseline gauze on the pad will help to ensure this. Opinions vary as to whether you should ever pad an anaesthetized eye. If you do pad it, there is a risk of the pad pressing against the eye. If you don't pad it, dust may get into it of which he is unaware!
SHIELD" HIS EYE: (1) After any severe injury, especially if there is a perforation. (2) After any operation. Shielding it allows it to open and close, without anything extraneous touching his cornea, and perhaps scratching it. A shield is the safest way to protect an anaesthetized eye, and is very helpful for a painful inflamed eye with photophobia.
Put a piece of sterile gauze across his orbit without touching his eye. Hold this in place with a strip of adhesive strapping diagonally across his orbit. Cut an 8 cm diameter circle from cardboard, or an old X-ray film. Cut a radius in this, fold it into a cone, and maintain the cone with a piece of strapping. Hold the cone in place with two pieces of adhesive strapping, or plastic tape from his forehead to his cheek.
CAUTION! Never occlude the eye of a child under 7 years for several days, because this may cause amblyopia (24.9).
Operating on an eye
Unless you have received special training, limit your surgery to operations on a patient's lids: entropion (24.13), tarsal cysts (chalazion, 24.12), tarsorrhaphy (30.3), and evisceration, enucleation, and perhaps exenteration of his eye (24.14).
Trauma is described in Chapter 60. Although Section 60.4 describes the repair of a-perforating injury, this needs good magnification, 8/0 or 9/0 sutures, and skill. So you would probably be wise to treat him non-operatively, and to give him subconjunctival gentamicin and atropine eye ointment.
EYE OPERATIONS EOUIPMENT. Don't operate with the large instruments of a basic set. Use the fine eye ones in Section 24.1. For operations on a patient's globe, an operating loupe and a bright focal beam are almost essential, preferably a 12 volt spotlight from a battery, or a transformer from the mains. A spirit lamp.
5/0 and 8/0 polyglycolic acid, silk, or monofilament sutures, all on 7.5 mm curved atraumatic needles. Monofilament sutures are better than silk on the cornea. 8/0 sutures are the finest ones that you can use without a microscope. Use virgin silk or nylon for the cornea, and catgut or polyglycolic acid for the conjunctiva. Nylon irritates if it is exposed.
PREPARATION, Prepare his face from his hairline to his chin and from ear to ear, using povidine-iodine 10%, or a nonalcoholic lotion which will not harm his eyes, if it enters them accidentally. Other surgeons use iodine and spirit, and take care to keep them out of his eyes.
Make a special drape with a slit from the middle of one end to the centre. Place this under his chin, and up each side of his face. Fold it over his head and keep it there with a towel clip. Place another drape across his forehead over his eyebrows, and clip this to the first one. If he is intubated, place a third drape over his nose and the catheter mount. If he is having a local anaesthetic, don't cover his nose or mouth.
ANAESTHESIA. You can usually use local (A 6.5) or general anaesthesia (A 16.9). Use general anaesthesia for a perforation (if local anaesthesia is complicated by retrobulbar haemorrhage, it may aggravate loss of eye contents).
POSITION the table so that you can sit comfortably, with your knees under it. If necessary, put his head at the foot end, or rest it on a plank, or sheet of wood, pushed under the mattress,and projecting beyond the table.
Sit your assistant on your right for a right eye, and on your left for a left eye. Keep your own eyes on the wound; ask him to place the instruments in your outstretched hand, and to hold them by their proximal ends, without touching their tips.
You can use a speculum, or lid sutures, to hold an eye open while you operate on it.
TO INSERT A SPECULUM, on a conscious patient instil two drops of local anaesthetic. Ask him to look down, grasp his top lid with your finger, and slip the top blade of the speculum under it. Then ask him to look up, grasp his bottom lid, and slip the lower blade of the speculum under that. Adjust the arm of the speculum until his eye is exposed, and then tighten the locking nut.
L!DSUTURES are not for suturing wounds, but to hold the lids away from an eye while you operate on it. They avoid the risk of a speculum, which may press on his eye, and perhaps scratch his cornea.
In his upper lid insert two 3/0 silk or monofilament sutures, just above his lash line and down to his tarsal plate. In his lower lid insert one suture just below his lash line. Don't penetrate the conjunctiva of either lid. Hold these sutures with haemostats.
BLEEDING, The cornea is avascular and cannot bleed. If his conjunctiva or sclera bleed, apply a pad and very gentle pressure. Or flood the wound with saline from a syringe and an irrigating needle, or an undine attached to a tube and silver cannula. The blood will stream in the clear saline, so that you can see the exact point where it is coming from, and control it with a cautery. Heat a squint hook or a small cautery in the flame of a spirit lamp, until it is hot, but not red hot. Touch the bleeding point with this, through the stream of saline. This will cool its tip enough to prevent burning, but will leave it hot enough to seal the bleeding vessel. Don't use diathermy.
The red painful eye
Acute red painful eyes are due to: (1) conjunctivitis (much the most common cause at any age). There are two particularly important forms of conjunctivitis in different age groups. (la) Ophthalmia neonatorum in newborn babies. (lb) The conjunctivitis associated with recent measles in children between the ages of 6 months and 6 years. There are also some important, but less common causes of an acute red eye: (2) A corneal ulcer. (3) Acute iritis. (4) Acute glaucoma. (5) Trauma is another cause, but the diagnosis is usually obvious from the history (Chapter 60).
The problem in a busy clinic is that conjunctivitis is so much more common than the rarer causes of a red eye, that these are easily missed. So your first task in managing red eyes is to make sure that these rarer causes are recognized. Twenty patients may have conjunctivitis, and the twenty-first a corneal ulcer, or acute glaucoma. A patient's history, his visual acuity, and the examination of his eye with a torch should enable you to decide which he has.
Conjunctivitis can be bacterial, viral, allergic, or chemical. Bacterial conjunctivitis is common in the developing world, and may be mild, or so severe that a patient's conjunctiva pours out pus, and his lids swell so much that he cannot open his eyes. Neglected bacterial conjunctivitis may be followed by a corneal ulcer and a corneal scar, or by perforation and endophthalmitis. Bacterial conjunctivitis needs an antibiotic. Viral conjunctivitis usually resolves spontaneously without one, if the cornea is not involved.
Besides infecting a patient's conjunctiva, bacteria can infect his lids (blepharitis), or his cornea, where they can cause: (1) Changes in the stroma (keratitis and sometimes a corneal abscess). (2) A corneal ulcer, which is a loss of surface epithelium. The danger of a corneal ulcer is that infection may spread inside his eye as an endophthalmitis, which may blind him.
A corneal ulcer may be due to: (1) Bacteria. (2) Herpes simplex virus. (3) Fungi. (4) Other conditions such as leprosy,causing lagophthalmos and exposing his cornea (30.3). Bacterial corneal ulceration can follow even a minor injury which damages the epithelium, or it can be spontaneous. Corneal ulcers are most easily seen when they are stained with fluorescein, which is why this is so useful.
When bacteria enter an eye through a corneal ulcer the first place they get to is the anterior chamber. If pus gathers here, and the patient stands upright, it falls to the bottom, with a straight upper fluid level called a hypopyon, as shown in C, Fig.24-7.
Endophthalmitis may be the result of: (1) A corneal ulcer,especially a bacterial one. (2) A perforating injury of his cornea or sclera, especially if a foreign body has been left inside his eye (60.9), or if a wound is neglected (60.4). Once bacteria have entered his eye, the chance of total blindness is high. If you see him early, when the infection is fairly localized, he may retain some useful vision; but if you see him late, the best you can do is to control infection, because his eye will be blind. If you cannot control it, you will have to eviscerate his eye (24.14).
RED PAINFUL EYES AND OTHER EYE INFECTIONS For the general method see Section 24.1. Acute iritis (24.5) and acute glaucoma (24.6) are described here as part of the differential diagnosis of a red eye, but are dealt with more fully later. Make sure you examine the patient in a good light.
THE DIAGNOSIS. If he has conjunctivitis, his discomfort or pain varies from mild to severe: (1) Both his eyes are usually involved. (2) His visual acuity is normally good. (3) He usually has a purulent discharge. (4) His conjunctivae are red, especially in his fornices. (5) His cornea is clear and does not stain with fluorescein (unless his conjunctivitis has caused a corneal ulcer). (6) His pupils are normal. (7) The tension in his globe is normal.
THE DIFFERENTIAL DIAGNOSIS OF CONJUNCTIVITIS. Distinguish particularly between the redness of conjunctivitis, which is typically maximal at the periphery, but is often uniform everywhere (very common), and redness-which is most marked at his corneoscleral junction (ciliary injection, less common).
CAUTION! Look for mucopus in his inferior fornix-it is always present in bacterial conjunctivitis; hesitate to diagnose conjunctivitis if you don't find any.
Conjunctivitis is usually bilateral: its important differential diagnoses are usually unilateral: Suggesting acute iritis-one (sometimes two) moderately painful red eye(s) with no discharge. His pain is often only mild, and he may complain of headache. Reduction in visual acuity, which may be only mild. Ciliary hyperaemia. A clear cornea. A small constricted pupil, which becomes irregular when you dilate it, due to posterior synechiae (adhesions). Look for an inflammatory exudate in his anterior chamber, preferably with a slit lamp: his aqueous is not as clear as it should be. The beam from the lamp shows a flare, like a beam of light shining across a dusty room. You may also see little lumps of cells (keratic precipitates or KP) sticking to the back of his cornea, and posterior synechiae between his iris and the front of his lens. The inflammatory cells in his anterior chamber may form a sterile hypopyon. His lOP (intraocular pressure) may be increased due to secondary glaucoma (24.6).
Suggesting acute angle closure glaucoma-one (seldom two) very painful red eye(s) with severe unilateral headache, and slight watering. Severely impaired visual acuity, often down to hand movements or perception of light only, with haloes, and sometimes even blindness. Ciliary hyperaemia (mild in the early stages). A hazy cornea (due to raised lOP) without its normal lustre. A shallow anterior chamber; this is best seen by shining a torch from the side. A vertically oval dilated pupil which does not react to light. A raised lOP (24.1).
Suggesting a corneal ulcer-one severely pai nfu I red eye with reduced visual acuity (if the ulcer is central), redness most marked round the limbus, photophobia, swollen eyelids, and watering. Look for a grey-white spot (the ulcer) on his cornea, which stains with fluorescein. If it is not obvious, look for a defect in the smooth surface of his cornea in the reflection from a focused light. If his ulcer is central, hyperaemia is equal all round his limbus. If it is near the edge, hyperaemia is more marked there. If his infection is severe, pus cells sediment at the bottom of his anterior chamber, with a fluid level (hypopyon). His pupil is usually regular. For treatment see below.
Suggesting a foreign body. The signs of an abrasion (60.4), and a foreign body (60.9), are similar to those of a corneal ulcer-unilateral pain, photophobia, a watery discharge, somtimes impaired vision, and ciliary hyperaemia, which may be localized to the region near the lesion. See also Section 60.4.
ACUTE INFECTIVE CONJUNCTIVITIS TREATMENT. Clean his eyes with a cotton swab and saline. Instil chloramphenicol eye drops or ointment hourly in severe infections, and 3 hourly in less severe ones. Or use tetracycline Ointment, with or without polymyxin and bacitracin. An eye ointment at night will prevent his lids sticking together. Continue treatment for two days after symptoms have resolved. Allow the exudate to escape, clean his eyes with a clean cloth and water, and don't pad them.
CAUTION! If his conjunctivitis is severe, watch carefully for a corneal ulcer, and if necessary examine his cornea with fluorescein.
If his corneae are not clear and his visual acuity is poor, he has a corneal ulcer (see below) and his sight is in danger.
CORNEAL ULCER TREATMENT is an emergency. Start aggressive treatment with antibiotics urgently. Admit him. He may be more comfortable with a pad or shield (24.1).
If his ulcer is severe, and particularly if he has hypopyon, give him a subconjunctival injection (24.1) of gentamicin 40 mg, or chloramphenicol 100 mg. Also, apply chloramphenicol drops, or tetracycline eye ointment hourly. Also give him systemic chloramphenicol (24.1, 2.9).
If his ulcer is not so severe, and he has no hypopyon, hourly conjunctival antibiotics and atropine ointment 3 times daily may be adequate.
Also, with any corneal ulcer, provided it has not already perforated, give him atropine eye ointment 2 or 3 times a day to keep his pupil dilated. This will prevent adhesions forming between his iris and his lens (posterior synechiae). Advise warm soaks (24.1). If there is any suspicion that he may be short of vitamin A, give it (see below). Complications include: (1) Diffuse scarring of his cornea (24.4). (2) A dense white scar (leucoma, 24.4). (3) Perforation of his cornea, with adherence of his iris, and perhaps staphyloma (an opaque protrusion of his cornea). (4) Endophthalmitis.
If his corneal ulcer is very severe, so that his whole anterior chamber fills with pus, he has endopthalmitis.
If his corneal ulcer has proceeded to the point where it has weakened, softened, and distorted his globe (pthisis bulbi) you will have to evisceFate it (24.14).
ENDOPHTHALMITIS (panophthalmitis) His anterior chamber is full of pus. Subconjunctival and parenteral antibiotics (24.1) are essential, but it usually too late for them to be successful, because the inside of his eye has become an abscess.
If his endophthalmitis is early, with some hope of vision, refer him urgently if you can. If not, try to control infection and minimize pain. Give him subconjunctival and parenteral chloramphenicol for 5 to 7 days. His infection may settle.
If his endophthalmltls Is due to a foreign body In his eye, remove it. It is usually superficial, so that you can remove it through the wound by which it entered, which is usually in his cornea, even if this has to be enlarged (60.9). Remove any prolapsing iris, and suture his cornea (60-6). Continue subconjunctival and parenteral antibiotics. Remove the sutures at 7 days.
'If he presents late, with no hope of vision and an anterior chamber full of pus, and shows no improvement in 48 hours, eviscerate his eye (24.14). The chances of sympathetic ophthalmia are negligible, so this is not a determining factor in deciding to remove it (60.10).
DIFFICULTIES WITH RED PAINFUL EYES If a NEONATE has RED SWOLLEN CONJUNCTIVAE with a PURULENT DISCHARGE, a few days after birth, he has OPHTHALMIA NEONATORUM, which may be gonococcal or chlamydia!. His cornea is usually clear, but may have an ulcer. This is an acute emergency, which may blind him. Clean away the pus with a swab and water, put tetracycline ointment into his eyes every hour. Give him penicillin, for example crystalline penicillin 30 mg/kg/day in 4 divided doses intramuscularly. Or, less satisfactorily, give him procaine penicillin forte 0.5 ml (30 mg) daily. Continue penicillin for 5 days.
If his conjunctivitis is very severe, and especially if he has a corneal ulcer, instil chloramphenicol eye drops every minute for one hour, every hour for one day, and then 3-hourly until he is better, and give him penicillin as above.
If he has an ACUTE RED EYE BETWEEN THE AGES OF 6 MONTHS AND 6 YEARS, the important condition is the combination of malnutrition, vitamin A deficiency, and recent measles. Look for: (1) Night blindness (inability to see in dim light). (2) Bitot's spots (white foamy spots on his lateral conjunctiva). (3) Xerosis (dryness of his conjunctiva with inability to produce tears, or a dry hazy cornea). (4) Keratomalacia (corneal ulceration, softening of his cornea). Give any child with any of these signs vitamin A 200,000 iu by mouth immediately,again after 24 hours, and again after 1 week. Also, give him a topical antibiotic such as tetracycline 1% 3 times daily. If his cornea is ulcerated, give him atropine eye ointment 1% once daily, and an eye pad. Improve his nutrition, and encourage his mother to give him plenty of dark green leafy vegetables.
If he has a CHRONIC LOW-GRADE CONJUNCTIVITIS with yellow-grey dots (follicles) under his upper eyelid, and he comes from an endemic area, he almost certainly has TRACHOMA caused by Chlamydia trachomatis. This goes through three stages described in Section 24.13; the important one to recognize is the second. During the acute stage, make sure he puts tetracycline eye ointment 1% or 3% into his eyes twice a day for six weeks. If his trachoma is severe, also give him a 14-day course of a sulphonamide or tetracycline.
Teach him to wash his face and hands well several times daily,and to avoid rubbing his eyes. Explain that his disease is due to the entry of dirt, often from flies. Apply tetracycline eye ointment to any case of acute red eyes, particularly when these occur as epidemics of conjunctivitis.
If LARGE GELATINOUS VEGETATIONS have formed on his upper tarsal conjunctiva, and look like cobblestones, or on the bulbar conjunctiva surrounding his limbus, suspect ALLERGIC CONJUNCTIVITIS. This is common in children and young adults. Their eyes are very itchy and water much. Suppress the inflammation with antihistamine drops or a very weak steroid. Beware of steroid glaucoma (24.5, 24.6D), because steroids, once started, may be needed for many years.
If he complains of PAIN AND WATERING WITHOUT ANY HISTORY OF A FOREIGN BODY, consider the possibility of a DENDRITIC ULCER. Stain his cornea with fluorescein and look for a branching irregular ulcer, which may also resemble the outline of an amoeba, or a country on a map. This is due to infection with the herpes simplex virus. He may think (wrongly) that "something has got into his eye". Dendritic ulcers occur all over the world, especially after fevers, particularly measles, malaria, and meningitis. In the industrial world they are now the most common and most damaging form of corneal ulcer; they commonly recur, and treatment is difficult. Refer him.
If you cannot refer him, if possible give him an antiviral agent: idoxuridine ointment (x5 daily), trifluorothymidine drops (hourly), or acylovir ointment (x5 daily). If his lesion is severe, combine this with mechanical removal of the epithelium containing the virus. Apply a topical anaesthetic, and stain his cornea with fluorescein. Using a loupe, a good light, and a ball of cotton wool on the end of an applicator, gently scrub the surface of his cornea in the region of the ulcer to remove its epithelium. A chronic stromal keratitis with corneal scarring and blindness can complicate herpetic eye disease.
CAUTION! Never apply steroids, because these may spread the infection to the stroma of his cornea, and make his condition worse.
If a CHEMICAL has got into his eye, his conjunctiva is intensely red (more so than in infective conjunctivitis), his cornea may be opaque (from keratitis or an ulcer), and his vision impaired. Unlike infective conjunctivitis, mucopus is absent. He may admit to having used traditional medicine for a painful eye, which has made it worse. If the chemical is still present, wash it out with much water. Give him an analgesic, and shield his eye. Instil an antibiotic ointment; its vaselene base will be soothing, and the antibiotic may prevent secondary infection.
If he has an acutely inflamed and oedematous lid or face, with a BLACK SLOUGH, and surrounding brawny oedema, and hides are used in the district, consider the possibility of ANTHRAX. His eyelid may be completely destroyed, but his eye is normal. Give him high doses of penicillin and sulphonamides. Anthrax responds rapidly to penicillin. Later, if necessary, toilet the slough and graft the raw area. If you leave raw lids ungrafted, severe scarring and a scar-induced ectropion may follow.
Loss of vision in a white eye
This is one of the common presentations of eye disease. Loss of vision in a white eye can be slow or fast. If a patient loses his vision slowly over months or years, he may have: (1) A corneal scar. (2) Cataracts. (3) Glaucoma. (4) A refractive error. Or, (5) disease of his retina due to: (a) Senile macular degeneration. (b)Retinitis pigmentosa. (c) Chloroquine maculopathy. (d) Old macular scars. Or, (6) optic atrophy. If he loses his vision suddenly over minutes or days, the cause is usually inflammatory or vascular (see below). If he complains that hecannot read, he usually has has presbyopia (24.8).
Corneal scars cause 700/0 of blindness in children and 25% in adults in the developing world. A corneal scar can be: (1) Diffuse. (2) A circumscribed white patch (leucoma). (3) A staphyloma, which is a bulging of the cornea forwards between the lids, due to the thinning, caused by previous ulceration. (4) Pthisis bulbi, which is disorganization of his entire eye, leaving it small and shrunken. Bilateral scarring follows ophthalmia neonatorum, vitamin A deficiency, traditional eye medicine, and trachoma. Unilateral scars are more likely to be caused by corneal ulceration due to bacteria, the herpes simplex virus, fungi, or trauma.
Cataracts cause about one half the blindness in the developing world, where they blind about one person in 200. 85% of cataracts are 'senile', and the rest are either congenital or familial, or due to trauma, iritis, or diabetes. A patient with a cataract presents with gradual loss of vision, in one or both his eyes. His corneae are clear, and there is an opacity in his pupil(s). A cataract can be immature (making his pupil grey), or mature, or hypermature (making it white). Sometimes a cataract swells, pushes the iris forwards, occludes the angle of his eye, and causes secondary glaucoma.
Removing cataracts is a standardized and repetitive task; it is also a skilled one and is never urgent, so it is not described here. If you want to remove them, apprentice yourself to an expert for several months, and try to remove at least 50 under supervision. Or, send an assistant to learn this skill. Cataracts can also be removed on a mass scale, particularly in Asia, in special 'eye camps'.
In good hands the chance of success is over 90% If a patient is operated on for the right indications, even moderate success in one eye only will enable him to be independent again. He is usually happy if he can see well enough to find his way about his home area. You will have to weigh up the benefits, and the risks, because vision without a lens is not normal vision.
There are two methods: (1) Removing the whole of his lens, within the capsule of the cataract (intracapsular extraction), which is the preferred method in the developing world. (2) Opening the anterior capsule, removing the cortex and lens, and leaving the posterior capsule (extracapsular extraction). This is safer in younger people « 30 years).
WSS OF VISION IN A WHITE EYE One or both eyes? Gradual or sudden? Family history? Any external factors such as trauma?
COMMON CAUSES OF GRADUAL IDSS OF VISION This is the patient who cannot see normally, and whose eyes are not reddened by conjunctivitis or ciliary injection. Examine him as in Section 24.1.
CORNEAL SCARS If the cause of the scar is still present, and it is getting worse,arrest it. Causes include scratching of the cornea by the in turned eyelashes of trachoma (trichiasis, 24.13; vitamin A deficiency causes an acute ulcer in young children, and does not cause progressive scarring). When you are sure that you have done all you can to prevent his scar progressing, manage him like this:
If he still has adequate vision in his other eye, he will not be severely disabled, and no treatment is indicated.
If he cannot see light at all, explain that nothing can be done.
If he is blind, and has a central leucoma which obscures his pupil, with an area of clear peripheral cornea, refer him for a optical iridectomy. This will give him an artificial pupil peripherally, behind his area of clear cornea, and should give him enough vision to make him mobile. It is contraindicated if he already has enough vision for mobility, or if he has no clear peripheral cornea.
If he is blind due to diffuse corneal scarring which has not made his eye perforate, consider referring him for corneal grafting. This is difficult and is usually impractical, because grafts and experts are scarce. Preferably, his cornea should have few vessels in it or none.
If his eye is blind and painful, consider eviscerating or enucleating it (24.14).
If he has any other kind of corneal scar, for example a unilateral corneal scaror pthisis bulbi, there is no point in referring him.
CATARACTS (1) Measure his visual acuity accurately in both eyes. His pupils should react briskly to light. If they don't, suspect that he also has some other condition, such as optic nerve disease. (2) Measure his lOP to make sure that his loss of vision is not due to glaucoma (24.6). (3) Dilate his pupil and examine his red reflex with an ophthalmoscope to assess how dense his cataract is, especially if it is immature. If you can easily see his optic discs, his cataract is not yet dense enough to be worth extracting.
INDICATIONS FOR EXTRACTION. (1) To improve his sight. (2) To treat complications, especially secondary glaucoma. If he has bilateral cataracts, operate when his acuity in both eyes has fallen to <6/60 (CF at 6 m).
If he has a unilateral cataract, surgery is only indicated to treat or prevent secondary glaucoma, or uveitis. It will not improve his sight.
If he has already lost the sight in his other eye for any reason, and he now has a cataract in his remaining eye (cataract in an only eye), delay surgery until he has difficulty getting around by himself and is nearly blind «CF 3 m), because any complication will make him totally blind.
If he has already had one cataract removed and is happy with his aphakic spectacles, his second cataract can be operated on at any time. But, because he can now see, he will be a low priority.
If his cataract is not ready for extraction, or if extraction is impossible, atropine ointment weekly, or minus (concave) glasses may improve his sight.
CONTRAINDICATIONS. (1) Unilateral cataracts with adequate sight in the other eye. (2) Bilateral small immature cataracts with acuity >6/60 in both eyes together-review his progress in 3-6 months.
If a cataract extraction is indicated, refer him.
POSTOPERATIVELY, if you have to care for him after he has been operated on by someone else, watch for a leaking wound (with or without iris prolapse), infection, bleeding, and a raised IOP. Gently open his lids, and examine his eye with a torch. If there is any iris prolapse, he must go back to the theatre, and have the iris excised and the wound resutured.
If his cornea is hazy with a striate pattern (striate keratitis), it will probably settle.
If his anterior chamber is shallow, the wound may be leaking. A firm double pad and bandage applied to his eye for 24-48 hours may stop the leak.
If there is blood in his anterior chamber (hyphaema), pad his eye and keep him in bed.
If there is pus in his anterior chamber (hypopyon), it may indicate postoperative infection (endophthalmitis). His eye is likely to be painful and his visual acuity very low. Give him subconjunctival gentamicin (24.1), topical antibiotics hourly and chloramphenicol by mouth.
If his red reflex is absent, there is some opacity in his media.
If he complains of much pain and his cornea is hazy, his lOP is probably raised (aphakic glaucoma); measure it. (1) His vitreous jelly may be blocking his pupil. Immediately dilate his pupil with cyclopentolate and phenylephrine drops, followed by atropine ointment for several weeks. If his wound is tight, his cornea clear, his anterior chamber deep and clear, and his pupil black, all is well. Give him +10 aphakic spectacles and discharge him between the 3rd and 10th postoperative day.
RARER CAUSES OF GRADUAL LOSS OF VISION IN A WHITE EYE Examine his macula and his optic cup with particular care. If an old person has gradual loss of central vision, atrophy, and irregular pigment at his maculae, suspect senile macular degeneration. There is no treatment.
If he has pale, white, flat optic discs (distinguish these from the pale cupped discs of glaucoma), and normal maculae, he has optic atrophy. Try to find the cause (there are many, including a space-occupying lesion around the optic chiasma). There is no treatment.
If he has gradual loss of vision at any age, often starting with night blindness, a family history, and dark pigmentation which follows his retinal vessels and takes the form of 'bone spicules', suspect retinitis pigmentosa. There is no treatment.
If he has gradual loss of central vision and has taken excessive doses of chloroquine (>10 tablets weekly for>1 year), suspect chloroquin maculopathy. His macula has a typical 'bull's eye' pattern with a dark centre and a paler surrounding ring. Stop chloroquin. There is no treatment.
If he has old macular scars (large white areas with black edges, often around his optic disc and his macula), they may be due to previous toxoplasmosis or toxocariasis. There is no treatment.
SUDDEN LOSS OF VISION IN A WHITE EYE(S) He has lost his vision over minutes or days, in one or both eyes, which are white.
If at any age he has steadily lost his vision over 24 hours,in one eye or occasionally both his eyes, suspect posterior choroiditis due to toxoplasmosis or other causes. The important sign is inability to see his retinal vessels due to hazy media caused by inflammatory cells in his vitreous. He may respond to systemic steroids, and he may resolve spontaneously. Give him atropine until the inflammation has resolved.
If symptoms started with a flash of light followed by black objects floating in his field of vision, and then a curtain or cobweb across it, suspect retinal detachment. Part of his retina may look grey-green. Dilate his pupil and examine his fundus. You will see an abnormal red reflex in one part of his fundus, with elevation of part of his retina, and tortuosity of its vessels, which are difficult to focus on. Expert surgery may save his sight.
If he has instantaneous loss of vison, suspect occlusion of his central retinal vein (a swollen disc with many haemorrhages all over his retina), or artery (a swollen disc, oedema of his retina, and often a cherry-red spot at his macula). There is no immediate treatment. If he has central retinal vein thrombosis, follow him for at least 3 months, because he may develop secondary glaucoma, which needs treatment.
If he has loss of central vision with an abnormal pupil response to light, suspect optic neuritis (any age, usually in the 3rd and 4th decades, and usually unilateral). His media and optic disc are usually normal. He will usually improve over about 8 weeks. Bilateral optic neuritis following methyl alcohol or drugs (quinine) is permanent. There is no specific treatment.
Uveitis; iritis and iridocyclitis (anterior uveitis), and choroiditis (posterior uveitis)
Any part of the uveal tract can become inflamed-the iris (iritis), the ciliary body (cyclitis), or the choroid (choroiditis). More than one part may be involved at the same time (iridocyclitis). The terms 'iritis' and 'uveitis' are often used loosely and interchangeably, and we will do the same here. Although iridocyclitis may be caused by bacteria invading the eye through a corneal ulcer (24.3), it and other forms of uveitis are more often due to a sterile inflammation, usually from an unknown cause. Uveitis of several kinds is common in the developing world.
Iritis (more strictly iridocyclitis) has several consequences: (1) A patient's inflamed iris may stick to his lens by posterior synechiae (adhesions, common) or less often to the back of his cornea by anterior synechiae. (2) If the entire margin of his pupil sticks to his lens, his iris balloons forwards (iris bombe, B, 24.7), and he has secondary glaucoma (24.6). (3) Small separated pieces of iris may stick to his lens, or less often to his cornea. (4) Abnormal proteins enter his aqueous, and cause an aqueous flare, which you can see with a slit lamp. You can also see leucocytes as tiny particles floating in his aqueous. (5) These particles may stick to the back of his cornea as keratic precipitates (KP), and they may be numerous enough to gather at the bottom of his anterior chamber as a hypopyon. Unlike the hypopyon that results from the entry of bacteria through a corneal ulcer, the hypopyon of iridocyclitis is usually sterile. Untreated iridocyclitis eventually subsides spontaneously, typically in about 6 weeks, leaving his eye severely damaged. It may relapse, or it may be insidious and chronic, with few symptoms except progressive loss of vision.
Uveitis presents in two ways (or in both of them together, panuveitis, see below): (1) Anterior uveitis (iritis) presents as an 'acute red eye'; it is thus one of the important differential diagnoses of this condition, and particularly ofconjunctivitis (24.3). He has pain in and around his eye varying from mild to severe, photophobia, watering, and often blurred vision. He has ciliary hyperaemia, and often general hyperaemia also. His pupil is constricted. (2) Posterior uveitis (choroiditis) presents as progressive loss of vision, without other obvious symptoms, in a white eye (24.4).
Iritis is usually a sterile reaction to one of the infections listed below. If onchocerciasis (24.7) is endemic in your district, it will certainly be the most common cause. Usually, no cause is found, and iritis is presumed to be an autoimmune disease.
Atropine will keep his pupils well dilated, and break down synechiae.
Steroids are controversial. Opinions differ as to their long term benefit, and whether they are safe in non-expert hands. They probably hasten resolution, and justify the risks associated with their use, but only provided that you don't use them if there is any sign ofinfection, especially a corneal ulcer. Remember also that: (1) Steroids will make a red eye white, regardless of the cause, without necessarily curing it. (2) They will suppress the normal inflammatory response, without killing the causative agent. (3) They may raise his intraocular pressure, and may cause a secondary glaucoma that could blind him (unusual). (4) If you give steroids long term, they may cause a cataract, but they will not do this during the few weeks that are necessary to treat acute iritis.
UVEITIS, iritis, iridocyclitis, choroiditis DIAGNOSIS. Uveitis may be unilateral, or bilateral, and presents in various ways.
Acute anterior uveitis (iritis, iridocyclitis) presents as a red, painful eye, with photophobia and tearing; for the differential diagnosis see Section 24.3.
Posterior uveitis involves mainly a patient's choroid, and presents as fairly sudden loss of vision over 24-48 hours in a white and usually painless eye, due to damage to his retina and an exudate of cells and pigment into his vitreous. After dilatation, you can see these as a vitreous haze with an indistinct retina. At a later stage, when the haze has cleared, you may see foci of white depigmentation, surrounded by heaped up black pigment which results in impaired vision, especially if it involves his macula.
Panuveitis (quite common) is a combination of anterior and posterior uveitis, and causes loss of vision in a red, painful eye.
SPECIAL TEST. Dilate his pupil and look for posterior synechiae which will confirm the diagnosis of iritis.
CAUSES. You will probably find no cause, but if he has any of these, it may be responsible: syphilis, leprosy, herpes, toxoplasmosis, toxocariasis, onchocerciasis (24.7), tuberculosis (29.1), trauma, or the leakage of the lens protein from a hypermature cataract.
TREATMENT. Dilate his pupil with short acting mydriatics (cyclopentolate and phenylephrine). When his pupil is dilated, maintain him on atropine ointment 1% three times a day, until his uveitis is no longer active, as shown by the absence of KP bodies and redness. This will prevent posterior synechiae, which would lead to the blinding complication of secondary glaucoma and cataract. So, keep his pupil dilated until all the inflammation
has subsided.
If his disease is unilateral, cover his eye with a shield (24.1) if it is severe, and a shade if it is not. If it is bilateral, give him eye shades made from exposed X-ray film.
STEROIDS. His iritis will subside spontaneously, but topical steroids will hasten its departure.
CAUTION! NEVER give steroids if: (1) There are signs of infection. (2) He has a corneal ulcer.
If he has anterior uveitis (iridocyclitis), instil hydrocortisone drops 1% into his conjunctival sac 3 hourly.
If he has posterior uveitis, give him tablets of prednisolone 20-30 mg/day for 3 to 6 weeks. Don't continue beyond 6 weeks. Tail these off for a week at the end of the course.
If his lOP is raised, also give him acetazolamide 250 mg 6-hourly, until the inflammation is under control. Double the dose if it remains raised. If possible monitor his lOP weekly by tonometry.
DIFFICULTIES WITH UVEITIS If POSTERIOR SYNECHIAE develop, they may be followed by a cataract. Or they may occlude his pupil and cause pupil block glaucoma (iris bombe), with an increased IOP. Be sure to dilate his iris vigorously with atropine, so that it does not stick to his lens.
If he gets SECONDARY GLAUCOMA, his pupil will not dilate. You can refer him for an iridectomy, but it is usually too late.
Glaucoma
Glaucoma is a group of blinding diseases in which a patient's intraocular pressure (lOP) is usually raised, causing damage to his optic nerve, and resulting in loss of vision. There are four kinds: (1) Primary (chronic) open-angle glaucoma (POAG). (2) Primary angle closure glaucoma (ACG). (3) Secondary glaucoma as a complication of trauma, swollen cataract, iritis, etc. (4) Congenital glaucoma (buphthalmos).
POAG occurs in eyes in which the angle between the iris and the cornea is normal, and is probably due to a block in the drainage of intraocular fluid at the trabeculum. POAG causes 10-20% of blindness in developing world, 90% of glaucoma in Caucasians, and most cases of glaucomatous blindness in Africans. Up to 1% of the over-40s may have it. POAG is bilateral, but is often asymmetrical; it is insidious and progressive, and causes no symptoms until a patient has lost much of his sight. Glaucoma cannot be prevented, and even early treatment cannot restore lost vision. The best that can be done is to recognize it early, and to prevent his vision getting worse. For this to be possible, all health workers must be aware of the possibility of glaucoma in any patient who complains of loss of vision. The key to early diagnosis is to pick up early changes in the optic discs and a raised lOP, both of which can be recognized by eye assistants. The aim ofmedical and surgical treatment is to lower the lOP to a level which will stop further damage to his optic nerve, and therefore preserve his vision at its present leveL Trabeculectomy (not described here) is a relatively simple operation, with a reasonable chance of preserving what vision he still has. It should be available at a referral hospital, or at another district hospital, where there is a surgeon interested in doing it. Learn it from an expert at the same time that you learn cataract extraction.
The symptoms of POAG are non-specific. The patient complains of slow loss of vision .in one or both his eyes over months or years ('loss of vision in a white eye', 24.4). Sometimes, he has marked loss of vision in one eye, while his other eye is normal,or nearly so. Occasionally, he has pain and headache, but this is late. Glaucoma is often familial, so inquire about blindness in his relatives.
Angle closure glaucoma (ACG, acute glaucoma) usually occurs over the age of 35, in women more often than men, with an abnormally narrow angle between the iris and the cornea. If this angle should happen to close a little more than usual, it causes a sudden abrupt rise in a patient's lOP, so that he presents with unilateral episodic attacks of pain, misty vision, and rainbow coloured haloes round lights. Between attacks his eye is normal. Sooner or later, an episode of raised lOP does not resolve, and he presents with classical acute congestive glaucoma ('loss of vision with a red eye', 24.3). Acute glaucoma is relatively uncommon, and is rare in Africa. Its incidence is high estjn Inuits and Mongolian peoples, in Burma, and in South East Asia.
The dangers of atropine in glaucoma result from its effect in dilating the pupil: (1) This keeps the iris away from the lens, and prevents adhesions (synechiae) forming between them, which is valuable in iritis when you want to prevent this happening. (2) Dilatation of the pupil crowds the iris into the angle of the anterior chamber, where it impedes the drainage of aqueous. This is never a desirable effect, but it does not matter in a normal eye or in iritis; it can however blind an eye if drainage is already impaired by glaucoma! So, do give atropine in iritis, but don't give it in glaucoma!
IF AN OLDER PERSON COMPLAINS OF POOR VISION, CHECK FOR GLAUCOMA.
GLAUCOMA
PRIMARY OPEN-ANGLE GLAUCOMA, 'POAG', 'chronic glaucoma'
DIAGNOSIS. Measure the visual acuity of any patient who presents with loss of vision. A hazy cornea or a pupi I which does not respond normally to light should make you suspect glaucoma. If his lOP is >28, or his cup/disc ratio is >0.5, he may have glaucoma. The end stage of glaucoma is a patient with a blind, or nearly blind eye, with a large pupil that does not react to light. Aim to diagnose it long before this with the following three tests. Loss of visual field is an early sign, but is not easy to test for with simple equipment.
CAUTION! (1) The lOP is useful in confirming glaucoma, but is not absolute. (2) Glaucoma can occur with a normal lOP (30% of patients with glaucoma have an lOP of < 22 mmHg). (3) A raised lOP is not always associated with optic nerve loss. (4) The lOP fluctuates, so if you are in doubt, repeat the measurements over a few days.
(1)LOSS OF VISUAL ACUITY is not an early sign in POAG, but it is a quick one. Always measure a patient's visual acuity, whenever he presents with an eye complaint (24.1).
(2)CUPPING OF THE OPTIC DISCS is the important sign. Chonic glaucoma causes the discs to become deeper and Wider, and the remaining rims of disc tissue to atrophy. One eye is commonly affected more than the other, so that a definite difference between a patient's two eyes is probably abnormal. Enlargement starts at the upper or lower margins, so that a vertically ovoid cup with a cup/disc ratio of >0.5 is probably abnormal. Eventually, the margin of the cup approaches the margin of the disc, so that only a narrow rim of tissue remains. Its wall becomes steep, so that vessels bend abruptly as they reach the level of the surrounding disc. If the edge of the disc overhangs the cup, you may lose sight of them until they appear over the edge of the cup. A large physiological cup can be difficult to distinguish from an early glaucomatous one.
With practice, eye assistants can distinguish 'normal discs', 'suspicious discs' and 'advanced glaucomatous cupping'. If you can only do one test, changes in the discs are the most useful one. If necessary dilate his pupils. Normal discs: (1) The discs are the same in both eyes. (2) The ratio of the optic cup to the optic disc is 0.5 or less. (3) The cup is circular and the periphery of the disc (the optic nerve rim) is pink. (4) The appearance of the disc remains constant over time.
Signs suggestive of glaucoma: (1) A cup/disc ratio of greater than 0.5. (2) A vertically oval cup, perhaps with notching at the upper or lower poles. (3) An area of pallor >30% of the disc area. (4) Asymmetry of the cup/disc ratio between the two eyes.
(3) ABNORMAL PUPIL RESPONSES are a useful way of testing for glaucoma, and only need a torch. Initially, one pupil does not react as briskly as the other. Finally, there is no response at all.
If you shine a light into a normal eye in a semidark room, its pupil will constrict(direct response), and so will the other pupil (consensual response).
If his optic nerve is completely destroyed, there will be no direct or consensual response (total afferent pupil defect).
If his optic nerve is partly destroyed (for example 90 0/0), his pupil will constrict slowly when the light shines in it (partial afferent pupil defect), showing that only a little optic nerve is functioning.
The swinging torch test, is a useful test for early asymmetrical optic nerve damage, and does not need an ophthalmoscope. It is theoretically difficult, but is easy in practice. In a semi dark room shine a light into his good eye, and then swing it across into his bad eye (the eye with reduced vision).
As the light shines in his good eye, the pupil of his bad eye will constrict. As you swing the light quickly across to his bad eye, its pupil, which was previously constricted, will now dilate. This indicates a relative afferent pupil defect, early optic nerve damage, and a difference in function between his two optic nerves.
The practical test is to swing the torch from one pupil to the other and back again in a semi dark room. If one pupil consistently dilates as light shines on it, that eye has a reduced pupil response, relative to the better eye, and should be investigated for optic nerve disease, perhaps POAG. THE RISK FACTORS FOR POAG are: (1)Age >40. (2) A positive family history in first-degree relatives. (3) Race, POAG is more common in Africans than in Caucasians. (4) A vertical cup/disc ratio of >0.5. (5) An lOP of >28 mmHg«2with a5.5 g weight).
MANAGEMENT will preserve what sight he has, but will not improve it.
If he is already blind in both eyes and unable to walk about by himself, it is too late to help him.
If he has any sight left (he can walk about by himself with either eye), refer him immediately for trabeculectomy. Even when his sight is as poor as CF 1 m (24.1), he may still derive some benefit from treatment. If you cannot refer him, or do a trabeculectomy yourself, you will have to try medical treatment:
Medical treatment can lower his IOP, but it has to be constant, consistent and continue for life, which is usually impracticable, so that immediate surgery is better. The drugs are: (1)Pilocarpine 4% 4 times daily. (2) Timolol 0.5% twice daily (expensive). This is a ß-blocker which reduces the secretion of aqueous. (3) Acetazolamide tablets 250 mg 4 times a day. Start him on pilocarpine or timolol, and if this fails to maintain his lOP <20 mmHg, also give the other drug. If both drops fail to lower his lOP below 20 mmHg, give acetazolamide 250 mg 1 to 3 times daily for short periods (side-effects may occur with continued use). To treat him effectively, you will have to measure his intraocular pressure, and monitor his visual fields regularly. This has to be done in a specialist clinic.
Surgical treatment is a trabeculectomy which removes a piece of the filter (the trabecular meshwork), and so allows his intraocular fluid to drain under his conjunctiva; this increases drainage and reduces his IOP. The operation has an immediate success rate of >80%, and is the recommended treatment for most patients with POAG in the developing world.
ACUTE GLAUCOMA This is is usually due to 'ACG' (angle closure glaucoma), but secondary glaucoma (see below) may occasionally present acutely.
DIAGNOSIS. He presents with an 'acute red eye' at any age (one of its rarer causes, 24.3), severe unilateral headache in and around his eye, and sudden profound loss of vision. When you examine him, his vision is reduced, his eye is red, his cornea is hazy from oedema, his anterior chamber is shallow, his pupil is usually dilated, and his intraocular pressure is usually over 40 mmHg.
CAUTION! He will go blind unless you treat him quickly.
TREATMENT. Admit him as an emergency. Refer him to an ophthalmologist as soon as possible, who will decide whether to do a trabeculectomy or peripheral iridectomy, or whether to treat him medically. If referral is delayed, start treatment before he goes. If you cannot refer him, you will have to treat him medically yourself. Give him an analgesic to ease his pain, and treat both his eyes. Aim to: (1) Lower his lOP by increasing the drainage of aqueous. Give him acetazolamide 500 mg orally followed by 250 mg 6-hourly, as soon as his nausea has subsided. (2) Keep his pupils constricted. This will keep the periphery of his iris away from the angle of his eye, where the aqueous flows out, and so help it to drain. Treat both his eyes with drops of pilocarpine 1-4% every 15 minutes, for 2 hours. If this makes his pupil constrict, the angle will be opened. (3) If necessary, you can also lower his lOP by increasing the tonicity of his blood. Give him 50 ml of flavoured glycerine by mouth. If he is nauseated, he may not tolerate this. Or, give him 200 ml of 20% mannitol intravenously during 20 minutes. When medical treatment has reduced his lOP to normal, he needs a peripheral iridectomy soon, to prevent a future attack, and probably a prophylactic one on the other side also.
CAUTION! (1) He can become totally blind in 12 hours, so treatment is urgent. (2) Rainbow-coloured haloes round lights,and misty vision, are important prodromal signs, and need urgent investigation and treatment. (3) Atropine can precipitate an attack in a patient with a shallow angle, so avoid it in such people.
SECONDARY GLAUCOMA This complicates: (1) Trauma, including hyphaema (blood in the anterior chamber, 60.8). (2) Swollen cataract (see below). (3) Some cases of iritis. Treat the primary condition, and refer him. If you cannot refer him, treat him with acetazolamide, mannitol, or glycerol as above.
DIFFICULTIES WITH GLAUCOMA If he has an acute RED PAINFUL EYE, a shallow anterior chamber with a hazy cornea, and a FIXED, DILATED WHITE PUPIL, he has a SWOLLEN CATARACT, causing secondary glaucoma. Give him acetazolamide 500 mg immediately followed by 250 mg 4 times daily, and refer him for removal of his cataract.
If he has LOSS OF VISION and has been using steroid drops for several months, suspect STEROID GLAUCOMA. Topical steroids cause a genetically determined rise in lOP in a third of people. This is sometimes severe enough to cause glaucoma, exactly like POAG. Stop steroids.
If a child has BIG EYES, which may be associated with photophobia, blepharospasm, and tearing ("...such beautiful big eyes"), suspect CONGENITAL GLAUCOMA (buphthalmos,ox-eye, rare), due to maldevelopment of the angle of his anterior chamber. The sclera of a child are soft, so that his eyes enlarge when his lOP rises. Other signs are: an increased IOP, a corneal haze (variable), sluggish reaction of his pupils to light, and enlargement of his cornea (> 12 mm), or of his whole globe. If necessary, treat him medically and refer him immediately.
Onchocerciasis
Onchocerciasis is a parasitic infection of the skin and eyes caused by Onchocerca volvulus, which is endemic in parts of West and Central Africa, with foci in East Africa and Latin America. In hyperendemic areas 60% of the population are infected: in such areas blindness rates may vary widely, but may be as high as 15% Microfilariae invade all parts of the eye: the cornea (keratitis), the anterior chamber (iritis), the retina (chorioretinitis), and the optic nerve (optic neuritis). Blindness and irreversible eye lesions are most often found in men of 30 and older. Try to identify the patients at high risk from the blinding complications, and to arrest their disease.
ONCHOCERCIASIS A patient from an endemic area complains of itching, with or without a rash. He may have skin nodules, night blindness (enquire about this), gradual loss of vision in both his eyes, and sometimes tearing and photophobia. Look for microfilariae in snips from his skin.
CORNEA. He has a sclerosing keratitis with opacification of the lower third of his cornea. Tongues of opacification invade his cornea from the 3 and 9 o'clock positions, or from anywhere in the lower half, where they may form an apron across his cornea. If he is not treated, opacification slowly advances upwards over his pupil, until all that may be left is a clear area at 12 o'clock.
Slit lamp microscopy shows 0.5 mm linear and fluffy opacities at all levels in the stroma, and minute wriggling microfilariae in his anterior chamber.
IRIS, The final stage is a small, non-reactive, down drawn, pear shaped pupil. Earlier stages are a loss of pigment in the margin of his pupil, exudation in front of, across, or behind it, posterior adhesions which turn it inwards, and small keratic precipitates (KP). A gelatinous exudate sometimes drags the lower margin of his pupil down and everts it.
Posterior synechiae and peripheral anterior synechiae lead to secondary glaucoma.
RETINAAN DOPTIC DISCS, Look for: (1) Diffuse white areas and black pigmented ones most marked temporal to his macula (the Ridley fundus). (2) Optic atrophy, with sheathing of the vessels close to the nerve.
TREATMENT. Ivermectin ('Mectizan') is the drug of choice. Ongoing (1988) community trials are using an annual dose of 150 μg/kg with encouraging results. The traditional drugs diethylcarbamazine (DEC) and suramin cause so many complications, including visual deterioration, that they are not recommended. Nodulectomy is usually only recommended for children with head nodules.
If he has an onchocercal iritis, dilate his pupil with atropine and give him topical steroids (24.5). If he develops secondary glaucoma (24.6), treat his onchocerciasis and then refer him for surgery.
Refractive errors, difficulty reading, and presbyopia
In terms of comfort, increased efficiency and the number of people who benefit, the prescription of glasses is among the most valuable procedures in medicine. So do what you can to supply them. The refractive errors are: (1) Myopia (short sight). (2) Hypermetropia (long sight). (3) Astigmatism (the refractive mechanism is aspherical). (4) Presbyopia (the common longsightedness of old age) (5) Aphakia ('no lens') after cataract extraction.
Presbyopia is part of the normal process of ageing: it appears earlier in the tropics than in higher latitudes, and is easily diagnosed and treated. It is responsible for 85% of the need for glasses.
Whereas a myopic child has to be specially fitted, because his eyes may not be the same, a presbyope can, if necessary, be left to choose the glasses which best suit him from a pile of second hand ones. Astigmatism is more difficult to correct, but it is usually so mild that it needs no correction. In the developed world, its correction is often overemphasized.
The visual acuity of all patients with refractive errors improves when they look through a pin-hole, which uses only their central vision. This is the basis of the pin-hole test (24.1).
REFRACTIVE ERRORS If a patient has astigmatism or hypermetropia, he needs retinoscopy, which you will not have been trained to do, so refer him.
If he cannot see at a distance but can read, he is myopic. Test each eye alone with minus spherical glasses starting with -0.5 dioptres, and increasing in 0.5 dioptre steps. The smallest minus number that gives him the best acuity is the prescription he needs.
If he is a child with reduced visual acuity due to refractive errors or squint, refer him.
If he is aphakic after a cataract extraction, try him with +10, 11 or 12 lenses for distance, and + 13, 14 or 15 lenses for reading.
DIFFICULTY READING PRESBYOPIA If a patient complains of difficulty reading books or newspapers, (1) Ask him his age. If he is under 40 he does not need reading glasses for presbyopia, so explain this to him. (2) Measure his visual acuity. If it is not good, see Section 24.4, otherwise proceed. (3) Examine his eyes to make sure they are white, and that he has no serious problems. If they are otherwise normal, you can give him glasses.
TO PRESCRIBE READING GLASSSES give him those with the lowest number (the weakest pair) which will let him read easily. A useful guide is: age 45 + 1.00, 50 + 1.50, 55 +2.00, 60 +2.50,65 +3.00. If he is choosing from a pile, he needs the weakest satisfactory pair (usually +2.00). Explain that they are only to be worn for reading and other close work, not for seeing in the distance.
Disease of the neuromuscular system of the eye (squints, amblyopia, and diplopia)
If a patient's eyes do not look in the same direction, he has a squint. Squints are common in the developing world, and are usually accepted with resignation. Although treating a squint needs relatively simple technology, it is time-consuming and needs skill, so squints will probably be low in your list of.priorities.
If his eyes do not look In the same direction, he will see two images. This causes confusion, and to avoid it he tends to suppress the sight in one of them. If this suppression continues for long enough, he may lose vision in that eye. This is called amblyopia, which is a reduction in vision, due to lack of use of an apparently normal eye. If amblyopia is not corrected by the age of 7, it becomes permanent. So try to diagnose and refer squints before this age.
SQUINTS AND AMBLYOPIA
SQUINTS DIAGNOSIS. The corneal light reflex and the cover test will demonstrate a manifest squint.
The corneal light reflex. Shine a pen torch directly in front of you, and ask the patient to look at it. If each of his eyes is properly fixing the torch, its reflection from his corneal mirrors will be the same, and more or less central on each cornea. Are the reflections from your torch equally centred on his pupils?
The cover test. Ask him to look straight ahead at some target in the distance. Cover his left eye, with a piece of paper. If his right eye moves, In or out, to fiX on the distant target, it was previously squinting. If it does not move, it was looking straight at the target.
Now put the paper in front of his right eye. If his left eye moves as you remove the paper, it was previously squinting in or out. If it does not move, he does not have a manifest squint, and both eyes look straight.
MANAGEMENT is limited. If an adult has a squint and no double vision it may be the cause of reduced vision in the squinting eye (amblyopia). There is no treatment at this age.
If an adult has a squint and double vision, this suggests a serious recent disease of his extraocular muscles or their nerves such as diabetic neuropathy, myasthenia gravis, or raised intracranial pressure. He needs a full medical and neurological examination.
If a child under the age of 7 years presents with a squint: (1) Dilate both his pupils, and use an ophthalmoscope to make sure that his squint is not due to a retinoblastoma in one of his eyes (an uncomon cause of squint, 32.7). Look for a yellowish mass on his retina. (2) If his retinae are normal, try to assess his visual acuity in both eyes. This may be possible if he is >3 years, but rarely if he is younger.
If he has reduced vision in either eye, or a definite squint, and he is under 7, refer him. He may need glasses, occlusion therapy to treat amblyopia, and perhaps surgery on his extraocular muscles.
CAUTION! Never occlude the eye of a child under 7 years for several days, because this may cause amblyopia.
If you cannot refer him, correct any refractive error and occlude the eye that he normally uses. Occlude it for 1/2 to 2 hours a day while he is doing close work, reading, or drawing. The duration of treatment depends on the duration of his ambylopia. If treatment is prompt, a 6-8 weeks of occlusion may be enough. If it is delayed he may need it for a year, or it may fail.
AFTER THE AGE OF 6 MONTHS NO SQUINT SHOULD BE IGNORED
Diseases of the lids and nasolachrymal apparatus
Diseases of the eyelids and nasolachrymal system include tumours, deformities of the lids, and watering (epiphora). Globally, the most important disease of the lids is trachoma, which scars them, and causes them to turn inwards (entropion, 24.13). The commonest and usually the most harmless disease of the lid is a stye.
THE LIDS If a patient has a red swelling on his lid margin, with an eyelash coming out of it, he has a stye (hordeolum). This is a staphylococcal infection of the follicle of an eyelash. Pull the eyelash out of the swelling, and give him an analgesic. Antibiotics are only necessary in recurrent styes, or if there are signs that infection is spreading beyond his lid (carotid sinus thrombosis is a rare complication, 5.5). Suggest that he tries hot spoon bathing (24.1).
If he has a swelling in either lld, some distance from its margin, pointing towards its conjunctival surface, he probably has a tarsal cyst, (chalazion, Meibomian cyst). Avoid an external scar by incising his conjunctiva wherever the cyst points.
If a few lashes turn in on the eye (trichiasis), remove them with a pair of forceps (epilation). They regrow, and need removing at regular intervals.
If most of his lashes or the margin of his lid is turned in (entropion), he needs surgery (24.13).
If the margin of either lid is everted (ectropion), usually as the result of scarring, seventh nerve palsy, or leprosy, surgery may be necessary (unusual).
THE NASOLACHRYMAL APPARATUS If a mother brings you her young child saying that he has had a watering eye since birth, he has congenital atresia of his nasolachrymal duct. It will probably resolve spontaneously by the age of 18 months. Reassure her, and give her a topical antibiotic to apply if he gets conjunctivitis. If his eye is still watering at the age of 2 years, his nasolachrymal duct needs probing and syringing. Refer him.
If something interferes with the drainage of an adult's tears, his eye waters (epiphora) even if there is no local irritation. He can usually learn to live with it, but epiphora can occasionally be so severe that it needs surgery (dacryocystorhinostomy). Refer him.
If he has a tender swelling between his eye and the side of his nose, he probably has acute dacryocystitis (an abscess in his tear sac). Give him a systemic antibiotic, an analgesic, and warm soaks (5.5).
Proptosis
If there is a space occupying lesion in a patient's orbit, it pushes his eye forwards. Proptosis is always serious, and it can be difficult to diagnose; so it is fortunate that it not common. Some of its causes (orbital cellulitis and Burkitt's lymphoma) need chemotherapy. Most of the patients who need surgery are either going to die from malignant tumours anyway, no matter what is done, or they have slow-growing benign tumours, which you have time to refer. So your ability to help a patient with proptosis is limited; but you should try to make a diagnosis.
Proptosis can occur slowly over years, or rapidly over days. Its causes vary geographically, and with the age of the patient. Here they are, the more common ones first; the later ones are mostly very rare:
An adult may have: (1) A retrobulbar haematoma following an injury (common, 60.8). This is only an incident in a head injury, and the diagnosis is obvious. (2) A mucocele of his frontal sinus (the commonest cause), due to an infection followed by an obstruction, which prevents his sinus draining into his nose. (3) Orbital cellulitis, or an orbital abscess, usually following frontal or ethmoid sinusitis (5.5), or occasionally trauma. (4) A pseudotumour of his orbit due to a granuloma ofunknown cause. (5) An epidermoid or dermoid cyst, which may be of the 'dumbbell' type, and extend into his anterior cranial fossa. Don't operate on these, unless you are skilled enough to dissect widely, and have made an accurate diagnosis. (6) A mixed lachrymal tumour (lachrymal adenoma). (7) A haemangioma or hamartoma; you may be able to empty a haemangioma temporarily by pressing it back into his orbit. (8) A hydatid cyst, if he comes from an area where these occur (31.13). (9) Cavernous sinus thrombosis (5.5). (10) A secondary tumour. (11) A malignant melanoma (32.20). (12) Carcinoma of his maxillary or ethmoidal sinuses (32.39) invading his orbit. (13) The hyperophthalmopathic form of thyrotoxicosis (dysthyroid eye disease, Graves's disease). (14) A meningioma of his sphenoid.
A child may have: (1) A retinoblastoma in the first 5 years of his life (32.7). (2) Acute ethmoiditis, commonly when he is about 2. (3) Burkitt's lymphoma, if he comes from the 'Burkitt zone' (32.3). He will probably have a jaw tumour also. (4) A rhabdomyosarcoma (32.9). (5) Some other kind of lymphoma (32.4,32.5). (6) A neuroblastoma. (7) A secondary tumour.
You can treat orbital cellulitis, abscesses, and cavernous sinus thrombosis (5.5) with systemic antibiotics. If you diagnose a retinoblastoma (32.7) early enough, you can enucleate the globe. Burkitt's lymphoma usually responds dramatically to chemotherapy.
PROPlOSIS HISTORY. Long history? (benign lesion). Short history? (malignant lesion or acute infection). Acute onset with pain? (infection).
EXAMINATION. Sit the patient down, stand behind him, look down on his eyes from above, and observe the relative positions his globes. This will help to distinguish pseudoproptosis, due to the relative widening of one palpebral fissure.
Hold a ruler horizontally, and measure the position of each cornea from the midline. If he has two proptosed globes, and they are both equidistant from the midline, he probably has thyrotoxicosis (the most likely cause of bilateral proptosis). If they are not equidistant, one globe has probably been pushed out of place by an orbital mass.
Examine his fundi for papilloedema and optic atrophy. Search him for signs of a primary malignant tumour.
CAUTION! Don't confuse proptosis with a staphyloma due to a neglected corneal ulcer (24.3). His normal intraocular pressure has caused his previously weakened cornea to bulge, in a manner which you can mistake for a tumour. His globe is however in its normal position.
X-RAYS may demonstrate: (1) Erosion of the bones of his orbit. (2) Sclerosis (typical of a meningioma). (3) Calcification (sometimes in a retinoblastoma).
BIOPSY may be practical. If a tumour is palpable externally, explore over it and take a biopsy, except for lachrymal adenomas, which should never be biopsied.
If it is not palpable externally, a lateral orbitotomy which splits his temporal bone may be indicated. Refer him.
DIAGNOSIS AND MANAGEMENT. See elsewhere for the management of orbital infections (5.5), especially draining pus (drainage through the lower or upper fornix is usually best), retinoblastoma (32.7), and Burkitt's lymphoma (32.3).
Acute «3 months) in an adult: orbital cellulitis, trauma, pseudotumour.
Acute « 3 months) in a child: acute ethmoiditis, retinoblastoma (0-5 years), Burkitt's lymphoma (5-15 years). Chronic (> 3 months) in an adult: frontal mucocele, thyrotoxicosis, lachrymal tumour, meningioma.
If his proptosis arose acutely, and his lids are red and swollen, perhaps with a fever and tachycardia he has orbital cellulitis, or an orbital abscess. Give him systemic antibiotics. If he has an abscess drain it.
If a child of about 2 years has sudden unilateral proptosis, with swollen lids and conjunctiva, fever and tachycardia, suspect acute ethmoiditis. Give him systemic antibiotics.
If he is very sick and with an acute pulsating proptosis, which may be unilateral initially, but soon becomes bilateral, with engorgement of the veins, and total inability to move his eye, perhaps with an associated meningitis, suspect cavernous sinus thrombosis (5.5).
If he has a swelling which has enlarged slowly (weeks or months) in the superior nasal quadrant of his orbit, pushing his eye downwards and outwards, he probably has a mucocele of his frontal sinus (common). Drain it through an approach between his periosteum and his frontal bone, keeping outside his orbit. Enter his sinus and drain the mucopus. Place a drain from his sinus into his nose. Suture his skin in layers. Remove the drain at 6 weeks.
If he is between 15 and 35, and his proptosis occurred over several weeks or months, suspect a pseudo tumour. The diagnosis is largely by excluding other causes. It will respond well to prednisolone 80 mg daily for 1 week, falling slowly to 5 mg daily by the 4th week. Maintain him on 5 mg a day for several months, or it will recur.
If he has a swelling of the upper lateral quadrant of his or bit, pushing his eye downwards and inwards, which has grown slowly over many months or years, he probably has a lachrymal adenoma. Don't be deceived by the small mass of tumour palpable externally: most of it will be inside his orbit behind his eye. It needs removing through a lateral orbitotomy. Refer him.
If the proptosis of thyrotoxicosis does not respond to medical or surgical treatment (21.8), try high dose systemic steroids. If this fails, refer him for the surgical decompression of his orbits.
SYMPTOMATIC TREATMENT FOR HIS EXPOSED CORNEA. Examine his cornea to make sure that it is not ulcerated. Apply antibiotic eye ointment 3 or 4 times daily, and especially at night. If necessary, protect it by tarsorrhaphy (58.28). Padding can be dangerous, because the pad may abrade and ulcerate his cornea.
Tarsal cysts (chalazions or Meibomian cysts) and granulomas
Cysts sometimes form in the Meibomian glands on the conjunctival side of a patient's tarsus. They present as a swelling in either lid, which may become chronically or acutely infected. Small asymptomatic ones need no treatment, and may resolve spontaneously. Incise an acute infection and curette a chronic one. These cysts are common everywhere, so that treating them is a common outpatient eye operation. Sometimes, they present as granulomas.
TARSAL CYSTS
EOUIPMENT. Chalazion clamp, No. 11 scalpel blade and curette.
ANAESTHESIA. Anaesthetize the patient's conjunctiva with drops of lignocaine 4%, or amethocaine hydrochloride 1%. Infiltrate his lid with lignocaine and adrenalin around the chalazion. Insert the needle at the upper margin of his upper tarsus,and the lower margin of his lower tarsus. Carry it forwards to his lid margin, on either side of the chalazion.
CURETTAGE. Evert his lid slightly. Put the chalazion clamp over the cyst, so that the solid blade lies on the skin of his eyelid, and the ring lies on his conjunctiva over the cyst. Close it so that it holds the lid and the cyst. Insert the tip of a No.11 blade, so that it cuts away from his eye. Alternatively, make a cruciate incision. Swab its contents clean.
CAUTION! Take care to curette away any pockets of granulation tissue, which may be hidden by a flap of conjunctiva, or have herniated themselves through his tarsal plate into his orbicularis muscle. If you don't do this, it may recur.
Remove the clamp and pinch his lid until it stops bleeding. If this is troublesome, wash it with warm saline. Place antibiotic ointment in his conjunctival sac 3 times a day for a week.
If the MATERIAL YOU INCISE IS HARD, and not gelatinous, suspect a carcinoma. Send it for histological examination, and refer him.
Entropion
Trachoma is the commonest eye infection in the tropics, and in its blinding hyperendemic form is the second commonest single cause of blindness and impaired vision (cataract is the first one). It is a chlamydial infection, which spreads from the eyes of one person to another, especially among children, in the poorest and most disadvantaged communities, particularly those in the Middle East and Africa. Trachoma is a chronic follicular conjunctivitis; it scars the conjunctiva of the eyelids and the cornea, and goes through four stages (see also Section 24.3):
1. The patient has a mildly red watery, eye due to bilateral conjunctivitis, especially of his upper lids, but without any distinguishing features. 2. Under his upper lid he has dilated blood vessels and hyperaemic, oedematous epithelial tissue (papillae). He also has yellow-grey swellings (follicles). Look at his corneoscleral junction with a loupe. If the edge of his cornea looks mildly grey, due to an arcuate (crescent-shaped) grey infiltration, and blood vessels go beyond the grey area into his cornea, he has pannus (meaning a curtain). This starts at the 12 o'clock position, and extends to 9 and 3 o'clock. Follicles and pannus indicate second stage trachoma. Follicles are not diagnostic, but pannus is. 3. The follicles in his lids become coarser and pannus spreads, sometimes across the pupillary area of his cornea. Scarring makes the margin of his upper lid irregular, and turns his upper tarsus inwards (entropion), taking his lashes with it, so that they scratch his cornea each time he blinks (trichiasis). This causes recurrent attacks of keratitis, which eventually end in a corneal opacity that blinds him. 4. Fibrous tissue replaces the follicles in his lids. This is the stage of cicatrized, or healed trachoma. His cornea is grey and scarred, his vision severely impaired, and his lids are deformed.
If you work in an endemic area, you are likely to have so many patients with entropion that you cannot refer them, so learn how to correct their eyelids yourself, and if necessary train an assistant to do this. The operation is always worth doing, even if his lids are severely scarred-his sight may recover suprisingly. Even if you fail, you are not likely to make his sight worse.
Several operations are possible: A tarsal plate rotation with a Inucosal graft from his mouth, is best. Unfortunately, this is more difficult and takes more time, which is important when you have many patients to treat. Instead, we describe two others. Opinions differ as to which is best. The difficulty is that if you do them and fail, you have crippled his lid, so that it is difficult for anyone else to do anything more. Radical eyelash excision (Malcolm Phillips) removes the lashes that scratch the cornea. This is simple; one contributor considers it the best operation and another the worst. If you can remove his lash follicles completely, his lashes cannot regrow, and so cannot scratch his cornea. Removing them is little cosmetic disability if he has a dark skin, and the relief that follows is dramatic.
Tarsal eversion is possible if his tarsal plate is firm enough to hold sutures. Cut a strip from its free margin, by incising from his conjunctiva outwards. This will free the edge of his upper lid, so that you can turn it through 1800 and sew it in place over the rest of his lid. This will give his upper lid a new edge, and make it about 3 mm shallower; but it will still meet the lower one when it shuts.
ENTROPION If only a few lashes are turning in, try pulling these out with forceps (epilation) without local anaesthesia. They may grow back so you may have to repeat this several times.
INDICATIONS. Trachoma which has distorted a patient's upper tarsus, so that it has curled inwards and made his lashes scratch his globe. Operate as soon as possible after entropion occurs.
You can operate on both his eyes at the same time, but if you do, you will have to admit him for 3 days, to allow the oedema of his eyelids to subside. Catgut sutures allow him to be discharged without needing to reattend.
EQUIPMENT. An eye set, a scalpel with No. 15 blade, 4/0 silk or chromic catgut.
ANAESTHESIA. Anaesthetize his upper lids through his skin with 1 ml of 2% lignocaine with adrenalin. Anaesthetize his conjunctiva with 2 drops of amethocaine, or lignocaine, or 4% cocaine.
RADICAL EYELASH EXCISION FOR ENTROPION (Malcolm Phillips) Start with his right eye. Use a scalpel to incise the margin of his upper lid, at the lateral end of his lashes, to a depth of 3mm as in Fig. 24-12.
Starting from either end, and using small sharp scissors, remove the margin of his lid bearing the roots of his lashes. Cut towards the medial end and preserve his punctum. Evert his lid as you do this, by pressing it with a swab. On his left eye, start at the medial end (if you are a right-handed operator).
Control the considerable bleeding that will result by suturing his conjunctiva to the skin of his eyelid with 3/0 catgut sutures on a cutting needle. Insert about 5 sutures, 5mm apart, and use them to hold little rolls of gauze. Apply an eye pad for 24 hours. Remove the sutures in 7 days.
TARSAL EVERSION FOR ENTROPION For this method, his tarsal plate must be stiff enough to take sutures. Using the anaesthetic method described above, place traction sutures of black braided silk in the centre of his upper lid, and at the junctions of its medial and lateral thirds with the middle third. Evert it over a roll of gauze, and clamp the sutures to a drape.
Using a No. 15 scalpel, make an incision about 3 mm from the inner margin of his lid, and parallel to it. Cut through his conjunctiva and the full length of his tarsal plate, at 900 to its surface, so as to free a strip from its edge. Curve each end of the incision towards the free edge of his lid, so that you can evert the strip of lid that bears his lashes.
Use skin hooks to retract the free edge of his lid. Use the tip of your scalpel to free the tissues from the anterior surface of the strip of tarsal plate for about 2 mm, until you see the follicles of his lashes in the base of the wound. Now undermine the anterior surface of the main part of the plate to a depth of about 4 mm. A little undermining like this will help you to mobilize the free edge of his tarsus. Do this in the plane between his orbicularis muscle and the insertion of his levator palpebrae superioris tendon.
CAUTION! Take care not to buttonhole his skin.
You can now rotate the distal fragment through 1800 as in F, Fig. 24-13. Insert 3 small mattress sutures of 4/0 chromic catgut, and knot them tightly so that they bury themselves and need not be removed. Or use cotton sutures, and remove them later. Put tetracycline eye drops into his conjunctiva 3 times a day for a week.
Destructive methods for the eye
If a patient has a blind painful eye, he may be better without it. This is one of the occasions on which the indications are more critical than the operation. If you cannot refer him, you will have to treat him yourself.
Evisceration is the least radical procedure; scrape out the contents of his globe and leave his sclera intact. This is is the only safe procedure if his eye is infected, because a sleeve of dura containing CSF surrounds his optic nerve. Other operations require that you cut it, and so open up a potential path of infection to his meninges. You may need to eviscerate his eye: (1) When antibiotic therapy fails to control a severe infection causing suppurative endophthalmitis, leading to orbital cellulitis, and oedema of his lids. If you don't eviscerate his eye and drain the pus from it, the infection may spread and cause cavernous sinus thrombosis and meningitis. (2) When he has a chronic less urgent infection in a blind painfull useless eye.
Enucleation (excision) removes his globe by dividing his conjunctiva, the extrinsic muscles of his eye, and his optic nerve. This can be done where there is no active infection; it is contraindicated when there is.
Exenteration is a bloody, mutilating operation. It removes the entire contents of his orbit, together with its periosteum, his globe, and all its extrinsic muscles. Consider doing this when he has a fungating malignant tumour of his eye or orbit. It will not prolong his life, but his last days will at least be more comfortable. He will be left with an empty orbital cavity, which you can line with split skin, or allow it to granulate. One contributor considers that exenteration has no place in this manual.
Removing an eye is not an operation to be done lightly: (1) The main indication for enucleation is persistent severe pain in a blind eye (see below). (2) If it has been injured, always try to repair it first, no matter how hopelessly injured it is (60.1). (3) He is unlikely to get a prosthesis, and the best one is his natural eye, even if it is blind.
DESTRUCTIVE METHODS FOR THE EYE Before you start any destructive operation: (1) Get signed permission from a child's parent or guardian. (2) Make sure you operate on the correct eye!
CAUTION! (1) Unless you are operating for malignancy or acute infection to save a patient's life, his eye must be totally blind. Test this with a strong light. (2) When pain is the main indication, it must be considerable. Pain is subjective, so make sure, if you can, that he really does have severe pain. See him on several occasions. If he has any sensation of light, leave it. It may become quite useful six months later. Don't take it out unless he implores you to.
EOUIPMENT. A basic eye set (4.12), a curette.
EVISCERATING AN EYE
INDICATIONS. (1) The failure of antibiotic therapy to control a suppurative endophthalmitis. (2) A blind, persistently painful eye, especially if it is infected.
ANAESTHESIA. (1) General anaesthesia. (2) If there is no significant infection, you can use the combination of a facial and a retrobulbar block (6.5).
METHOD. Incise his conjunctiva at its junction with his cornea, using fine-toothed forceps and fine scissors. Cut through the margin of his cornea with scissors. Excise his entire cornea. Scoop out all the contents of his eye with a curette or a periosteal elevator.
Pack his sclera for a few minutes to control bleeding. Then look inside to make sure that no black choroid remains. If necessary, wipe it away with guaze. If any does remain, he runs the remote risk of sympathetic ophthalmitis (60.10).
If you are operating for acute infection, leave it open to drain.
If you are operating for chronic infection. excise a 5 mm triangle of sclera from each side, to help make his globe collapse. If you wish, fill the remains of his globe with antibiotic drops. Suture the edges of his sclera together with 5/0 plain catgut, or leave them open.
If he can get an artificial eye, insert a plastic conformer shell.
POSTOPERATIVELY control bleeding by bandaging two eye pads firmly over the socket. Leave the dressing on for two days. Clean his lids and lashes twice daily, and put two drops of chloramphenicol 0.5% into the socket. Discharge him. He will be ready for an artificial eye in a month.
ENUCLEATING (EXCISING) AN EYE INDICATIONS. (1) A malignant intraocular tumour (retinoblastoma or melanoma) is an absolute indication. (2) A blind, persistently painful eye, which is not infected (evisceration is an alternative). (3) A penetrating wound, especially in the ciliary region, complicated by plastic iridocyclitis, and entanglement of the iris, lens capsule, and vitreous. If you leave an eye like this, sympathetic ophthalmitis may follow. Steroids are so effective that enucleation is very rarely necessary for sympathetic ophthalmitis (60.10). It is useless, if the second eye is already involved.
ANAESTHESIA. (1) General anaesthesia. (2) A retrobulbar block using not less than 6 ml of lignocaine, combined with a 7th nerve block (A 6.5).
EOUIPMENT. A minor surgical set.
METHOD. Incise his conjunctiva at its junction with his cornea, using fine-toothed forceps and fine scissors. 'Circumcise' it, and undermine it back to the insertion of his extraocular muscles, about 8 mm from the edge of his cornea. Push closed scissors through his conjunctiva to open up the plane between his conjunctiva and his globe. Open them to expose his sclera, anterior to the insertion of his rectus muscles. Snip Tenon's capsule between the insertions of these muscles. Pass scissors through the incision, until you have defined the muscle insertions.
Slip a squint hook under his medial rectus muscle, and pull it into view. If he is to have an implant, lift the muscle and insert a mattress suture of chromic catgut through its belly, about 3mm from its insertion. Clamp its insertion, remove the squint hook, and cut the muscle with scissors.
Separate each rectus muscle in the same way. Leave the stump of his medial rectus tendon a little longer, so that you have something to hold his globe with.
Make his globe prolapse forwards out of his orbit by closing the arms of the speculum behind it, and pushing them backwards. If his eye is so enlarged, that it will not fit between the blades of the speculum, pull it forwards by holding the stump of his medial rectus muscle with a haemostat.
Pass a pair of curved scissors, with their blades closed, down the medial side of his orbit, feel for his optic nerve behind his eye, open the scissors, and cut it. If you are excising it for a malignant tumour, cut it as far posteriorly as you can, because it may have been infiltrated by tumour.
Pull his eye forwards, and cut any tissue that remains attached to it. Put a hot wet pack into his orbit, and press on it until bleeding stops.
If he is to have an implant, it will probably be a simple glass globe. Place it in the muscle cone, and Tenon's capsule, and suture his conjunctiva over it.
If he is unable·to have an implant, close his conjunctiva and Tenon's capsule separately with 5/0 catgut. Irrigate his socket with 0.5% chloramphenicol.
EXENTERATING AN EYE INDICATIONS. A malignant tumour of his orbit, usually a retinoblastoma, which has penetrated his globe and caused proptosis.
ANAESTHESIA. You must use general anaesthesia. Have blood for transfusion available.
EQUIPMENT. A general set, periosteal elevators.
METHOD, If his lids have been involved by the tumour, suture their margins together with 3/0 silk. Use a No. 15 scalpel blade to cut round the margins of his orbit. If his lids are not involved, incise closer to his scleral margins, so as to save all, or some, of the skin from his lids to line his empty orbit.
If he bleeds profusely from the upper inner margin of his orbit, control it with diathermy. If you don't have diathermy, operate swiftly, and apply a pack. Incise the periosteum round the margin of his orbit, and reflect it as far posteriorly as you can. It is firmly adherent at the suture lines.
CAUTION! (1) The bone on the medial wall of the orbit is very thin, so elevate the periosteum here with special care. (2) The tumour may have eaten through the wall of his orbit, into his brain. If so, you may find it difficult to know where you are.
The periosteum should strip easily until you reach his orbital fissures, and his nasolacrimal duct. Cut this. Separate his palpebral ligaments, his trochlea, and his inferior oblique muscles from the bone with his periosteum.
Use curved scissors to cut the structures entering through his orbital fissures. Pull the contents of his orbit forwards, and cut the tissues at its apex with strong scissors as far back as you can.
He will bleed profusely. Remove the contents of his orbit, and then control bleeding.
Turn the skin at the edges of his orbit back into it. Graft its raw surfaces with split skin, either now or as a secondary procedure in 10-14 days. Gently pack his orbit. If you are not grafting it, dress it with acriflavine wool, and apply a firm bandage.
DIFFICU LTI ES WITH DESTRUCTIVE METHODS FOR THE EYE If he REFUSES TO HAVE A PAINFUL EYE enucleated or eviscerated, consider injecting absolute alcohol behind it to destroy its sensory nerves. You can use any strength of alcohol, provided it is more than 50%, but you may need to repeat the injection if pain returns. Permanent relief is uncertain.
Retrobulbar alcohol is very painful for about 30 seconds, so give him a retrobulbar block of lignocaine 1 ml (A 6.5). Remove the syringe and needle. When the block is effective, put another syringe on the needle and inject 2 ml of alcohol. His orbit will become severely oedematous for 10 days. Give him chloramphenicol eye drops 4 times daily for a week.
Other eye problems
Here are some of the other eye problems you may meet.
OTHER EYE PROBLEMS If he has a BLIND, PAINFUL EYE, it may be better removed. See Section 24.14.
If CANNOT OPEN HIS EYE he has PTOSIS. This may be congenital (refer him), traumatic (refer him), acute as the result of an oculomotor palsy (refer him), or the result of myasthenia gravis (treat him).
If he has A SMALL YELLOWISH-WHITE LUMP adjacent to his cornea in the region exposed by his palpebral opening, he has a PINGECULA. It is harmless, reassure him.
If he has a wing-shaped vascular THICKENING OF HIS CONJUNCTIVA which grows on to his cornea, usually from the medial side (common), this is seldom serious. If his vision is good, leave it. If it is advancing over the centre of his cornea and impairing his vision, refer him. If you cannot refer him, under local anaesthesia excise the pterygium off his conjunctiva, and dissect it off his cornea. Leave his sclera bare, and gently diathermy it. Up to 50% recur.
If an old person has a complete or incomplete WHITE RING ENCIRCLING HIS CORNEA about 1mm within the limbus, he has ARCUS SENILIS. It is harmless, reassure him.
If A PATIENT IS WORRIED ABOUT HIS EYES, they are both white, they have good visual acuity, and he is under 40 years old (that is, he is not presbyopic), and there is nothing obviously abnormal, you can reassure him that his eyes are normal.
