ATTACHMENT OF THE LID TO THE OCCIPITO-FRONTALIS MUSCLE
There are three chief methods of affecting this attachment:—
(a) By cicatricial bands (e.g. Hess’s operation).
(b) By a suture left permanently in position (e.g. Harman’s operation).
(c) By the attachment of the skin of the lid to the muscle (e.g. Panas’ operation).
Indications. In the majority of the cases of congenital ptosis the levator palpebræ is completely absent, as shown by the want of upward movement in the lid, and it is for this condition that one of the operations of this type is performed. In rare cases the occipito-frontalis muscle is also absent or imperfectly developed, and in these cases these operations should not be undertaken.
Hess’s operation. The object of this operation is to insert silk stitches between the eyelid and the occipito-frontalis muscle, and to leave them in long enough for a fibrous band of union to form along the stitch tracks.
Instruments. Scalpel, dissecting forceps, needle and holder, spatula, artery forceps.
Operation. First step. The eyebrow having been shaved, an incision 2 inches long is made about in the line of the brow, and the skin is dissected down almost to the lid margin.
Second step. Three sutures are passed, one in the middle, and one at each end of the lid; each suture carries two needles. The needles are inserted in the intermarginal line of the lid about 3 millimetres apart and brought out into the wound above, so that the lid margin is held by the loops. These threads are then carried deeply beneath the upper edge of the wound into the substance of the occipito-frontalis muscle, brought out through the skin well above the eyebrow and tied over a piece of drainage tube. The sutures should be drawn tight enough to produce an undue amount of retraction of the lid, as this tends to drop again after removal of the sutures. The skin wound is then closed and a small dressing is applied to cover the drainage tube on the forehead. The eye itself should be covered with a celluloid shield, as it is usually impossible for the patient to close the palpebral aperture, and the cornea is liable to be injured by exposure. The deep sutures should be left in for at least three or four weeks, so that they may bring about a fibrous band between the muscle and the eyelid by their irritation. The immediate result of the operation is usually excellent, but the lid is very apt to drop again in the course of six months or a year after removal of the stitches.