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.
Fig. 24-14 EVISCERATING AN EYE. A, the patient's conjunctiva has already been incised and undermined. Stab a No. 11 scalpel blade through his cornea into his anterior chamber. B, continue the corneal incision with scissors. C, excise his cornea completely. D, scoop out the contents of his eye with a curette. E, cut a triangular section out of each side of the hole in his sclera. F, inspect the inside of his eye to make sure that no choroid remains. After Galbraith JEK, ''Basic Eye Surgery' (1979), Figs. 9-17 to 9-24. Churchill Livingstone, with kind permission.
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.
EQUIPMENT. A basic eye set (4.12), a curette.
EVISCERATING [s7]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).
EQUIPMENT. A minor surgical set.
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.
Fig. 24-15 ENUCLEATING A PATIENT'S EYE. A, incise his conjunctiva. B, undermine his conjunctiva for about 8 mm. C, slip a muscle hook under each rectus muscle, bring it forwards into the wound, and cut it. D, draw his eye forwards by pulling on the insertion of his medial rectus muscle. E, cut his optic nerve from the medial side. F, cut any remaining adherent tissue. G, suture his conjunctiva with catgut. After Galbraith JEK, ''Basic Eye Surgery' (1979), Figs. 9-9 to 9-15. Churchill Livingstone, with kind permission.
ENUCLEATING [s7](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).
EQUIPMENT. 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 betwen 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 3 mm 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 [s7]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[nd]14 days. Gently pack his orbit. If you are not grafting it, dress it with acriflavine wool, and apply a firm bandage.
DIFFICULTIES [s7]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.