A porcine model predicts that a can-opener capsulotomy can be done safely in pediatric patients

Abstract

Purpose: The purpose of this study was to compare the strength and safety of a continuous circular capsulorhexis (CCC) with a can-opener capsulotomy (COC) in a porcine model that closely resembles the high elasticity of the human pediatric lens capsule. Methods: COCs (N = 47) and CCCs (N = 102) were performed inside the anterior chamber of fresh pig eyes, and any uncontrolled tears were noted. The circumference of the initial opening was measured in 18 COCs and 13 CCCs. After the opening was stretched to the point of rupture, the circumference was measured again. The ratio of the circumference at rupture to the initial circumference, minus one, was used as a measure of the maximal capsular strain. Results: The can-opener technique produced a smooth round opening. One of the COCs (2.1%) and 23 of the CCCs (22.5%) had uncontrolled tears (c 2, P <.001). The mean maximal strain for COCs was 46.7% (SE, 8.3%) and for the CCCs, 47.7% (SE, 9.9%). This difference was statistically not significant ( P = .93 by Student's t test). Conclusions: The porcine capsule is more reliably opened with fewer uncontrolled tears by a COC than by a CCC. The porcine model predicts that pediatric capsules can be opened safely with a COC. (J AAPOS 1999;3:356-62)