Fig. 1. Annular keratectomy techniques: steps for adult aphakia. A. Trephine keratotomy, 0.3 mm deep. B. Annular keratectomy, 0.3 mm deep and 0.5 mm wide. C. Spreading technique, 1 mm undermined. D. Lens edges designed to fit keratectomy. (Durrie DS, Brightbill (eds): Corneal Surgery, 2nd ed. St. Louis, CV Mosby, 1993)