Third step. The incision forming the upper margin of the crescentic piece of skin is deepened until it meets the incision made in the fornix, so that the lower lid is converted into a band of tissue attached only at each end.
Fourth step. The upper margin of the incision in the fornix is stitched to the upper margin or concavity of the crescentic piece of skin after the latter has been displaced upwards beneath the band of tissue carrying the lashes, and the lower margin of the crescentic piece of skin is stitched to the conjunctival edge of the band, so that the crescentic piece of skin is folded on itself and forms the new lower fornix, being held down in its position by the pedicle (Fig. 138). The sutures should be of catgut, as their subsequent removal is somewhat difficult.
Fifth step. The surface wound is closed by silkworm-gut sutures. The socket should be packed with gauze, or else a piece of style wire should be inserted, as in the previous operation, so as to maintain the groove in the new lower fornix.
CHAPTER VIII
OPERATIONS UPON THE EYELIDS
SURGICAL ANATOMY
The eyelids consist of well-marked planes of tissue, which are, from without inwards—
1. Skin with very little subcutaneous fat.
2. Orbicularis muscle.
3. Tarsal plates, which are attached to the orbital margins by the palpebral ligaments and which thereby form a barrier to the passage of infection backwards into the orbit.