Part 44 (1/2)

=Operation.= _First step._ The spatula is inserted into the superior fornix. A curved incision is made directly below the orbital margin throughout its whole length. The skin and orbicularis muscle are divided and dissected downwards so as to expose the upper surface of the tarsal plate. A suture is then pa.s.sed through this flap so that it may be drawn down by an a.s.sistant.

_Second step._ A narrow strip about 3 millimetres broad is excised from the whole length of the tarsal plate; in doing this care must be taken not to b.u.t.ton-hole the conjunctiva or flap of skin.

_Third step._ The cut margin of the tarsal plate is sutured to the levator palpebrae and palpebral ligament by two sutures pa.s.sed in the following manner: A thick catgut suture armed with a curved needle is pa.s.sed through the upper cut margin of the orbicularis palpebrarum, palpebral ligament, and levator palpebrae (if the latter be present) at about the junction of the middle and inner thirds of the wound, a firm hold being taken on these structures. The needle is then pa.s.sed through the tarsal cartilage parallel to the lid border for a distance of about 3 millimetres and out again on to its anterior surface. The needle is then again carried through the levator palpebrae, palpebral ligament, and orbicularis in the upper part of the wound. A similar suture is pa.s.sed about the junction of the middle and outer thirds of the wound. When both sutures are in position they are tied sufficiently tightly to produce the retraction of the lid desired, slight over-correction being necessary. The skin wound is then closed with sutures.

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 palpebrae 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 st.i.tches 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 st.i.tch 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 pa.s.sed, 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 s.h.i.+eld, 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 st.i.tches.

=Harman's operation.= The aim of this operation is to insert a fine metal chain between the occipito-frontalis and the lid, the chain being left permanently in position. The operation has not yet been performed sufficiently often to allow any definite statement about the final results to be made.

The results have not been very satisfactory in three cases in which the author has performed this operation.

=Instruments.= A 4-inch straight surgical needle, to which is attached the fine wire chain such as is used by spectacle makers to attach gla.s.ses to the dress. It measures about O.75 millimetre in diameter. It is attached to the needle by a soldered ring or by means of a piece of silk doubly looped through the needle without a knot.

=Operation.= Under a general anaesthetic. 'The method of implanting the chain will be followed readily by reference to Fig. 140. The chain-needle is inserted above the external angular process at A, is pa.s.sed inwards, and with a slightly upward inclination deeply beneath the tissues of the forehead, to be withdrawn at B; as much of the chain is drawn through as desired. The needle is reinserted at B, pa.s.sed beneath the brow close to the orbital margin and through the tissues of the lid to C, where it is withdrawn and the chain after it. In like manner it is pa.s.sed from C to D through the substance of the tarsus and withdrawn. It is now returned from D to E above the brow and withdrawn, and a final length embedded above the brow from E to F, which is just above the internal angular process. The chain should be buried completely and stretched evenly between the points A, B, C, D, E and F; and by traction the loop BCDE should be adjusted at B and E; when the lid is at the desired height the slack at B and E is taken up by traction on A and F.

'The position of the points E and B is of importance; they must be situated in the region of the most effective elevation of the brow by contraction of the frontalis muscle, as determined by experiment before the commencement of the operation (and they should be placed well above the eyebrow).

[Ill.u.s.tration: FIG. 140. HARMAN'S OPERATION FOR PTOSIS.]

'The lengths of chain lying buried above the brows from A to B and E to F, and the angles A B C and D E F, are arranged so that there is sufficient holding power to prevent the subsequent drop of the lid, but will not prevent adjustment to forcible traction on the lid until the links of the chain have become interwoven and surrounded by the growth of connective tissue. This growth should be sufficiently vigorous by the end of a week to securely fix the chain against all the force of traction of the orbicularis muscle. (In one case in which the author removed the chain after two weeks there was no connective tissue in the links and it was easily withdrawn.) Until this time the free ends of the chain should be turned towards each other over the skin of the brow and cemented in position by a cotton-wool and collodion dressing, after which time the free ends, A and F, are cut off and the free extremities pushed beneath the skin.'

=Panas' operation.= In this operation a direct adhesion of the skin of the lid to the occipito-frontalis muscle is aimed at.

=Instruments.= Lid spatula, scalpel, dissecting forceps, scissors, sutures.

=Operation.= Under a general anaesthetic.

_First step._ An incision, 2 inches long, is made in the line of the brow, and an incision of a similar length is made into the skin of the lid about half an inch below it. The tissue between these two incisions is undermined so as to produce a band of skin and subcutaneous tissue.

From the ends of the lower wound vertical incisions are made into the lid, running slightly outwards and inwards respectively towards the outer and inner canthus (Fig. 141).