Answer:
Causes of postblepharoplasty ectropion include: excessive removal of skin, fat, or muscle; scar contracture; damage to orbicularis oculi muscle; lid edema; adhesions of the orbital septum; hematoma; lax lid margin; proptosis; and elongated eyeball.
Patient conditions which predispose to ectropion and scleral show include: hypotonicity (e.g. lower lid laxity), prominence of the eye secondary to malar hypoplasia or shallow orbit, Graves' Disease, elongated eyeball, and previous blepharoplasty.
Preoperative evaluation should be directed to identifying any predisposing conditions and adjusting the operative procedure accordingly. For example, horizontal shortening (wedge tarsectomy) should be performed in the presence of lax lower lids, while on the other hand, in the presence of prominent globes, horizontal shortening should be avoided and lateral canthal elevation (tarsal strip procedure) should be done instead. During elevation of the eyelid skin, the pretarsal orbicularis muscle should be preserved. Careful excision of an appropriate amount of fat should be performed with fastidious hemostasis. Excess skin should be carefully excised with the patient's mouth open. The orbital septum should not be sutured to avoid vertical shortening. An occlusive lid suture (Frost suture) is often used to provide additional support for the first 24 hours post-op. To reduce hematoma and edema, cool and moist dressings should be applied, the head kept elevated for 72 hours, and a low-salt and alcohol-free diet should be followed. Sutures should be removed early at 2 or 3 days to reduce lid edema with start of eyelid massage to prevent fixation of protein-containing edema fluid with the subcutanous tissue and septum with subsequent eyelid attraction.