Instruments. Knife, forceps, scissors, spatula.
Operation. Complete. As narrow a strip of tissue as possible is removed from the lid borders behind the eyelashes. This is best performed by everting the upper lid and shaving off the posterior margin with a sharp knife; the lower lid is then treated similarly. The raw areas are brought into apposition with fine sutures.
Partial. When only a temporary adhesion is required, as after ectropion operations, it is sufficient to make raw corresponding areas of about 2 millimetres on the posterior margins of the top and bottom lids on either side of the central position of the cornea and unite them with sutures, which may be removed about the end of the first week.
PTOSIS OPERATIONS
The following operations are usually only undertaken for congenital ptosis, but they are occasionally required for the paralytic and traumatic varieties. All the operations are far from satisfactory, and should only be undertaken when the lid covers the pupil completely or so nearly that the head has to be thrown back to see objects directly in a line with the eyes. The relative value of the various operations apart from their indications is a matter of opinion amongst ophthalmic surgeons; therefore the various types of operations which are performed are given below.
There are four types of operation, which respectively aim at—
1. Shortening the eyelid by excision of a portion of the tarsal plate.
2. Attachment of the lid to the occipito-frontalis muscle.
3. Advancement of the levator palpebræ muscle.