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[md]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 mucosal 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 180[de] 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.
Fig 24-12 RADICAL EYELASH EXCISION (Malcolm Phillips). A, the direction of the incision. B, the part of the inverted eyelash to be excised. C, a suture passed through the lid. D, a small gauze pad tied to the eyelid. E, the operation complete.
RADICAL EYELASH EXCISION [s7]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 3 mm 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, 5 mm apart, and use them to hold little rolls of gauze. Apply an eyepad for 24 hours. Remove the sutures in 7 days.
Fig. 24-13 EVERTING THE TARSUS for late trachoma. A, the patient, showing his inturned upper lid, with his lashes scratching his cornea. B, a normal eyelid. C, a lid scarred with trachoma, with its lashes rubbing against his cornea. D, making the incision. E, his lid everted with tension sutures. The incision has been made, and the superficial surface of the tarsus gently undermined in both directions. F, the margin of the lid has been rotated and sutured in place. G, the completed lid. Kindly contributed by Roy Pfaltzgraff.
TARSAL EVERSION [s7]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 90[de] 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 180[de] 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.