Role of Tenon's capsule in postoperative restrictions.

Management of all restricted strabismus cases is difficult and frequently will require two or more procedures. The prevention of these restrictions at the time of primary surgery is far more important. All tissue should be handled as gently as possible, with smooth or fine-tip forceps, avoiding large fixation devices. Sharp dissection is essential - tissue should not be torn but cut carefully and sharply with scissors under direct visualization. The conjunctival and Tenon's capsule incisions should not be made directly over the muscle; this will result in scarring of the muscle to Tenon's capsule or of Tenon's capsule to the muscle insertion stump, promoting restriction. The muscle should be isolated under direct visualization or inspected carefully after isolation, with great care taken not to incorporate any unnecessary Tenon's capsule in the muscle and to avoid the inferior oblique msucle on lateral rectus muscle surgery. A blind, deep sweep is completely contraindicated. The intermuscular membranes, check ligaments, and muscle foot plates must be completely severed, under direct visualization, well beyond the resection site in the course of a resection,and 5 to 8 mm. behind the insertion in the course of a recession. Complete hemostasis during the procedure and at its completion is essential; 2.5 percent phenylephrine and minimal cautery will help achieve this. Since cautery will result in a scar of Tenon's capsule to that area of the sclera, it should be used as little as possible. Phenylephrine 2.5 percent has been used safely with halothane anesthesia in many patients without significant arrhythmias. The secondary treatment of restriction is very difficult, whereas their prevention requires only good surgical technique and careful attention to detail.