Emergency War Surgery NATO Handbook: Part IV: Regional Wounds and Injuries: Chapter XXIV: Wounds and Injuries of the Eye
United States Department of Defense
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Enucleation. Under no circumstances should an eye be excised by a general surgeon in a forward unit unless the globe is completely disorganized.
In the unlikely circumstance that a patient with a severe ocular injury cannot be evacuated within several days to a facility that has an ophthalmologist and the ophthalmologist cannot be brought to the forward facility, primary enucleation should be considered if the patient has no light perception using the brightest available light source. Such a severe injury would most likely be an extensive corneoscleral laceration with either prolapse or loss of intraocular contents. However, even in the face of a severely damaged eye with no light perception, cosmetic function may remain; therefore, consultation with an ophthalmologist should be sought before such a definitive procedure is undertaken.
Be assured that this policy of delay is perfectly safe as it relates to sympathetic ophthalmia. Sympathetic ophthalmia (involvement of the uninjured eye) never develops until at least ten days after trauma, and only very exceptionally develops before 21 days. There is sufficient time for the patient to reach an ophthalmologist.
If the decision is made to remove the eye, the conjunctiva is incised at the limbus to separate it from the globe. Using a combination of blunt and sharp dissection, the four rectus muscles are exposed from their insertions as far posteriorly as possible (usually 10-15mm). Tenon's capsule (the connective tissue surrounding the globe) is separated from the globe in the four quadrants between the rectus muscles. The extraocular muscles are then cauterized and severed 2mm from their insertions on the globe.
Traction should be exerted on the globe in the anterior direction as a curved Halsted clamp is placed behind the globe as deeply into the orbit as possible. By blunt dissection, the optic nerve is isolated, clamped to crush the central retinal vessels, and cut distal to the clamp. The globe is removed from the orbit. Before the Halsted clamp is removed, hemostasis should be achieved by direct cautery of the nerve stump. If available, it is most important to place a silicone sphere no larger than 16mm in diameter in the position occupied previously by the globe. The sphere should be placed within the muscle cone, posterior to the posterior layer of Tenon's capsule, and a careful closure of posterior Tenon's and anterior Tenon's, using interrupted 4-0 chromic catgut sutures, is completed. The conjunctiva is closed horizontally with interrupted 5-0 plain catgut sutures. If available, a ring conformer should be placed between the bulbar and palpebral conjunctiva to prevent obliteration of the conjunctival cul-de-sacs which impairs the patient's subsequent wearing of a prosthesis. A scleral ring, rather than a scleral shell type of conformer, is preferred because the ring eliminates direct pressure on the conjunctival suture line.
In the event that the patient still retains light perception or even better vision in the face of a corneal or scleral laceration, primary closure of the wound should be performed by the nonophthalmologist physician if the patient cannot be treated by an ophthalmologist within a few days. The guiding principle is meticulous wound closure without debridement, except for the excision of prolapsed intraocular tissue.
Magnification of any type will be of great assistance. Instruments should not be introduced through the wound into the eye. If the laceration involves both the cornea and sclera, the cornea should be repaired first. The smallest (7-0) silk suture material available and the finest available instruments should be used. The first suture should not be placed until the edges of the wound are carefully aligned. Close attention to the limbal landmarks will assist in proper alignment. The curved needle is introduced almost perpendicularly into the tissue about 2mm from the wound edge, and is taken to midstromal depth (the cornea is less than 1 mm thick in most areas) from where it is directed horizontally to the edge of the wound. The needle should penetrate the other edge of the wound at midstromal depth, and exit the cornea 2mm from the wound edge. The interrupted sutures should be placed every 2mm.
Scleral wounds should be closed similarly, using meticulous technique and midstromal depth placement of sutures. Noncolored sutures are usually used on the scleral wound, since these will remain buried after the conjunctiva is closed.
As a final note, all individuals rendering care for ophthalmic injuries must be aware of the frequent occurrence of combined neurosurgical and maxillofacial injuries when the eye and orbit are involved. Optimal treatment in these cases depends upon a well-coordinated team effort.
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