Operation. Under a general anæsthetic.
First step. A spatula is inserted into the upper conjunctival fornix. An incision is made just below the eyebrow over the upper margin of the tarsal plate throughout its length. The skin, especially of the lower margin of the wound, is dissected up and the orbicularis muscle divided, the tarsal plate, with the superior palpebral ligament attached to it, and the orbital margin being exposed. The superior palpebral ligament is then divided carefully high up near the orbital margin and directly below, in a small quantity of fat, will be found the tendon of the levator palpebræ superioris. The tendon can usually be distinguished from the palpebral ligament by the fact that it is elastic when pulled on.
| Fig. 142. Ptosis Operation. Advancement of the Levator Palpebræ. Showing the suture passed through the tendon; the difficulty of the operation is to find it. (Diagrammatic.) | Fig. 143. Ptosis Operation. Advancement of the Levator Palpebræ. Showing the sutures in position. The tendon is shortened by folding it on itself. |
Second step. The advancement of the muscle is then performed in one of the three following ways: (a) by excising a portion of the tendon and suturing the divided ends together; (b) detaching the tendon from the tarsal plate and bringing it from behind forward through a hole made in the upper margin of that structure and suturing it on its anterior surface towards the lower margin; (c) by folding the tendon on itself. The last method is the one most usually performed. Two sutures with a needle at each end are passed through the substance of the muscle and tied (Fig. 142). The ends of these sutures are then carried downwards between the tarsal cartilage and the orbicularis palpebrarum and out in the intermarginal line of the eyelid. The sutures are then tied tightly so as to secure rather more than the amount of retraction required (Fig. 143). The palpebral ligament and orbicularis palpebrarum are then united and the wound in the skin is closed.
GRAFTING A PORTION OF THE SUPERIOR RECTUS INTO THE LID
Motais’ operation. Indications. This operation is performed for cases of ptosis in which there is partial or complete loss of upward movement of the lid. In cases of congenital ptosis the superior rectus is not infrequently absent or imperfectly developed, as is shown by the defective upward movement of the eye. It need hardly be said that it is most important to see that the superior rectus is well developed before undertaking the operation. Vertical diplopia always follows the operation, and therefore it is advisable only to undertake it when the ptosis is bilateral, a similar operation being performed on both sides. Another somewhat hypothetical objection is that during sleep the eyelids are rolled upwards by the superior recti so that the lids are slightly open, but this occurs in almost all successful ptosis operations. Occasionally there is some defective upward movement of the eye after the operation.
Instruments. Speculum, straight strabismus scissors, lid retractor, needle holders and stitches.
Operation. A general anæsthetic is desirable in all cases.
First step. The superior rectus is exposed through a horizontal incision in the conjunctiva, as in the first stage for advancement. The tendon is defined in the wound and a strabismus hook passed beneath it; its middle portion is isolated and two silk sutures, with a needle at each end, are passed through it and tied.
Second step. The speculum is removed and the eyelid everted and pulled upward by means of a retractor or two silk stitches passed through the substance of the lid. Starting from the middle of the wound the conjunctiva of the fornix is divided backwards and the under surface of the tarsal plate is exposed.