Influence of size of neodymium:yttrium-aluminium-garnet laser posterior capsulotomy on visual function

Abstract

Purpose The aim of this study was to examine the influence that the size of a neodymium:yttrium-aluminium-garnet (Nd:YAG) laser capsulotomy performed for posterior capsule opacification (PCO) has on visual acuity (VA), and on contrast VA and that in the presence of glare (glare VA).Methods A total of 41 consecutive eyes with PCO first underwent Nd:YAG laser capsulotomy of smaller than pupillary size, after which the capsulotomy was secondarily enlarged, 2 weeks later, to greater than pupillary size. Best-corrected VA, and contrast VA and glare VA under photopic and mesopic conditions were measured after the small and large capsulotomies were made.Results After enlargement, the mean capsulotomy area increased significantly from 4.8 to 15.3 mm2 (P <0.0001). Best-corrected VA did not improve significantly after enlargement (P = 0.1282). However, photopic contrast VA and glare VA at moderate to low contrast visual target before enlargement were significantly worse than those after enlargement (P≤0.0242); furthermore, mesopic contrast VA and glare VA improved significantly after enlargement (P≤0.0431).ConclusionContrast VA and glare VA with a small capsulotomy were significantly worse than those with a large capsulotomy, which suggests that a capsulotomy larger than the pupillary size is necessary to restore contrast sensitivity and glare disability. © 2010 Macmillan Publishers Limited All rights reserved.