Instruments. Speculum, fixation forceps (two pairs), straight scissors, strabismus hook, strong curved scissors.
Operation. Before the anæsthetic is administered the forehead should be marked over the eye to be enucleated, so as to guard against the accident of removing the wrong eye. It is usual, at any rate in the case of hospital patients, to get their written consent for the operation.
First step. The speculum is inserted. In the case of the right eye the conjunctiva is seized with the fixation forceps downwards and outwards, or in the case of the left eye, downwards and inwards. The straight scissors being held with the right thumb and ring finger, the conjunctiva is divided freely all the way round, as close as possible to the cornea, and dissected back.
Second step. The capsule of Tenon is opened below the external rectus by grasping it with forceps and buttonholing it with the scissors. The strabismus hook is passed through the opening made in Tenon’s capsule with its concavity against the globe, turned upwards beneath the tendon, and the latter is pulled well forward and freely divided from above downwards between the hook and the globe. The superior and inferior recti are treated in a similar manner. In dividing the internal rectus a small portion should be left attached to the globe, so that subsequently it can be grasped with forceps to rotate the globe outwards when dividing the optic nerve.
Third step. The globe is dislocated between the lids by opening the speculum widely and pressing it backwards. If the globe will not dislocate, it is either because the tendons are imperfectly divided, or the palpebral aperture is too small to allow of its delivery; the latter is liable to be the case in small children or in those with a staphylomatous globe. In such cases the palpebral fissure should be enlarged by dividing the outer canthus.
The fourth step is the division of the optic nerve. The globe is rotated strongly outwards, either by pulling on the tendon of the internal rectus or by pulling the globe outwards with the finger; the optic nerve is felt for by passing the strong curved scissors behind the globe. When the nerve is defined the blades are opened widely, pressed backwards, and the nerve divided. The globe is then pulled forward with the finger, and the oblique muscles and remaining attachments divided. Hæmorrhage is easily controlled by pressure and the use of adrenalin.
Fig. 134. Enucleation. Method of suturing the conjunctiva; the suture requires no knot.
Fifth step. When the bleeding has ceased, the conjunctival wound is united in a horizontal direction by means of a thick silk suture running over and over; no knot is required and the ends are left long, so that it may subsequently be removed easily (Fig. 134). The usual dressings are applied with a firm pressure bandage for the first six hours. The suture should be removed at the end of the seventh day. No artificial eye should be worn for at least six weeks after the operation, and then only for a few hours at a time until the conjunctiva becomes accustomed to it. It should always be taken out at night.
Complications. These may be immediate or remote.