Controlled encircling procedure for retinal detachment.

The encircling operation for the treatment of retinal detachment is a well established surgical method (Schepens, Okamura, Brockhurst, and Regan, 1960; Regan, Schepens, Okamura, Brockhusrt, and McMeel, I962; Girard and McPherson, I962; Schepens, I964; Brockhurst, I965; Schepens, I968). However, complications do occur and a number of these are related to the tightness of the encircling band. Where this produces an insufficient ridge, the indent may not be enough to close the hole. If the ridge is too great problems of anterior segment ischaemia (Schepens, Okamura, and Brockhurst, 1957; O'Day, Galbraith, Crock, and Cairns, I966), strap pain, scleral necrosis (Okamura, I965; Kurz and Ezrow, I965), gross reduction of visual field, and meridional folds (Schepens, I964; McDonald, I965; Ferguson, I965) can occur. In an attempt to reduce these complications a method was devised to produce a smooth even ridge of standard depth. A 2-mm. high indenting ridge was arbitrarily selected. The reduction in diameter of a sphere at the site of a 2-mm. indentation would be the initial diameter (D) less 4 mm. (Fig. i).