When leprosy involves the ophthalmic division of a patient's fifth nerve, his cornea becomes anaesthetic. When it involves the zygomatic branch of his seventh nerve, his orbicularis muscle is paralysed, so that he cannot shut his eyes properly (lagophthalmos). The combination of these two lesions can have a devastating effect on his sight.
An anaesthetic cornea prevents him from noticing that he has something in his eye, or that it is dry. He loses his blink reflex, so that, even if he still has enough power in his seventh nerve to blink, he does not wash and wet his conjunctiva automatically. As a result, his cornea may be unprotected, especially while he sleeps, so that it may develop exposure keratitis, and ulcerate. If the centre of his cornea becomes opaque, his sight is spoilt. So warn him of the danger of an anaesthetic cornea, and examine his eyes regularly.
To decide if his cornea has been damaged, look for superficial scars, and use fluorescein drops, or papers, to search for central staining. If his cornea is anaesthetic, his eye is at great risk. If he has lagophthalmos, but his cornea is not anaesthetic, he may have enough sensation to complain of discomfort or burning.
To find out if he has significant lagophthalmos, ask him to close his eyes. If his cornea is completely covered, all is well. But if any part of it remains exposed, something must be done to protect his sight. Several operations are possible, but we only describe two methods of tarsorraphy. Both aim to reduce the gap between his lids when he tries to shut them. Tarsorrhaphy has cosmetic disadvantages, but it does save sight, and it is not difficult, so you should be able to do it if you care for leprosy patients. One of the most effective procedures, transfer of the temporalis muscle, is too difficult to be described here.
Fig. 30-1 TWO METHODS OF TARSORRAPHY FOR LAGOPHTHALMOS. This is a condition in which a patient's eye will not shut and waters excessively (A). B, pinch his lids together and tell him to open them. This will tell you how long a tarsorraphy needs to be to protect his eyes and still allow him to see. C, the incisions for Margaret Brand's tarsorraphy. D, two mattress sutures inserted. E, the incisions for McLaughlin's method. F, the suture about to be tied. G, the lid sutured. A, B, C, and D, from ''Watch Those Eyes' by Margaret Brand, with kind permission. E, F, and G, after McLaughlin from McDowell F and Enna CD, ''Surgical Rehabilitation in Leprosy', (1973). Williams and Wilkins, with kind permission.
LAGOPHTHALMOS [s8]IN LEPROSY If a patient has any weakness in his eyelid muscles, teach him exercises for them, such as screwing up his eyes as strongly as he can.
INVESTIGATION. Test the sensation in his cornea with a wisp of cotton wool. Examine his lachrymal apparatus. If patency is in doubt, dilate the punctum and irrigate the sac with saline. You may be able to flush out the system. If it remains blocked, but there is no sign of infection and no regurgitation of mucus, you can operate, but he will need an antibiotic postoperatively.
NON-OPERATIVE TREATMENT. [f41]If his paralysis is recent, treat him medically for a few weeks to see if it will recover. Warmth protects nerves in leprosy, so in cold weather ask him to keep his face warm with a woollen Balaclava helmet or a scarf.
If he has anaesthesia but not lagophthalmos, the stimulus to blink will be missing, but not the power to do so. So teach him to blink regularly.
(1) Artificial tears or even paraffin drops twice daily will help to protect his cornea. If you don't have medicinal paraffin, use the domestic kind. (2) Apply antibiotic eye ointment 3 times daily, especially at night. (3) Strap his upper lid to his cheek to prevent exposure of his cornea.
If he has a Type One reaction, give him steroids, as in Section 30.1a.
If his cornea is already ulcerated, give him antibiotics and atropine (24.3) until his cornea heals.
If he has iritis, dilate his pupil with atropine, and consider giving him topical steroids (24.5).
INDICATIONS FOR TARSORRAPHY. Any part of his cornea remaining exposed when he tries to shut his eyes. (1) Leprosy; if his cornea is already damaged, or he has reduced or absent corneal sensation and lagophthalmos, tarsorraphy is urgent. (2) Burns (58.28). (3) Facial paresis or paralysis; Bell's palsy. (4) Degloving injuries.
CONTRAINDICATIONS. (1) A cornea which is already damaged. (2) Lagophthalmos which is only temporary and will recover when the neuritis of a leprosy reaction recovers.
TARSORRAPHY [s7](Margaret Brand) CHOICE OF SITE. You can do a medial, or a lateral tarsorraphy. Close the medial or lateral half of his palpebral fissure with a pair of forceps, to determine which site is likely to be best, and how long the tarsorrhaphy should be. A medial one keeps the punctae in touch with the globe, and helps to relieve excessive tearing, which is common when the lower lid sags, as in A, Fig. 30-1. It is better cosmetically, but is more difficult, because the punctae and canaliculi are close to the operation site, and must not be damaged.
CAUTION ! The tarsorraphy must be large enough to enable him to cover his whole cornea, when he tries to close his eyes. A common mistake is to make it too small, so that it is ineffective. You may have to do medial and lateral tarsorrhaphies at the same time, leaving a small opening through which he can just see.
A temporary central tarshorraphy may be indicated, if ulceration threatens his cornea, or has already occurred, particularly if sensation is poor.
METHOD (lateral tarsorraphy). You can operate on both eyes at the same session. Pinch his lids together to decide how much lid to suture. Mark the appropriate length of lid with a little gentian violet. Instil a few drops of amethocaine 2%. Inject 1 ml of local anaesthetic solution with adrenalin (optional) into each lid near the margin (A 5.3).
Hold his lids apart and make an incision along the grey line (just behind the lash follicles), between the marks you have made with gentian violet. Make another incision parallel to the first one and 1 or 2 mm from it. Dissect away a strip of tissue between these two incisions. Repeat the procedure on the second lid to leave two opposed, raw, bleeding areas. Join these areas with monofilament mattress sutures every 5 mm. Swab away all blood clot, and tie them over lengths of fine rubber or plastic tube, to prevent them cutting into his skin.
CAUTION ! Make sure that no lashes project back between the sutures.
Preferably, cover his eye with a light dressing for 24 hours, and remove the sutures on the 14th day. If you have operated on both his eyes at the same time, leave them uncovered, and insert antibiotic drops 3 times daily until his lids have healed.
LATERAL TARSORRAPHY [s7](McLaughlin) Incise his lower lid margin along its intermarginal line (the line where his lids touch anteriorly) medially from his outer canthus for 5 or 6 mm. Remove a piece of the anterior lamella of the lower lid. Split the intermarginal line of his upper lid for the same distance, and remove a similar sector of tarsus and conjunctiva.
Evert his upper lid, and insert a 4/0 mattress suture from the skin to the bare area. Insert it through the bare area of his lower lid towards his conjunctiva. Then return, making a mattress suture about 3 mm long tied over a piece of fine rubber or plastic tube. When you tie it, his palpebral fissure will be shortened, and his lids will overlap.
Fig. 30-2 HANDS AT RISK. The area of skin in contact with the cylinder is black. A, and B, when a normal hand bears the weight of a block or a cylinder, most of its surface bears its weight. C, and D, when a clawed hand does the same too much of its weight is borne by the finger tips.E, and F, the same phenomenon when a patient lifts a box. This misuse of the finger tips is an important cause of finger absorption. From Brand Paul W, ''Clinical Mechanics of the Hand', (1985) Mosby, with kind permission.