Pharmacologic prevention of posterior capsule opacification: In vitro effects of preservative-free lidocaine 1% on lens epithelial cells

Abstract

Purpose To assess the in vitro effectiveness of preservative-free lidocaine 1% in removing lens epithelial cells (LECs) from the anterior capsule and to evaluate the effect of lidocaine on the LECs. Setting Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA. Methods Eight rabbits (16 eyes) were used in the study. After the rabbits were killed, the eyes were enucleated and divided into 2 groups. In Group 1 (n = 8 eyes), LECs were exposed to preservative-free lidocaine 1% or balanced salt solution (BSS®) for 1, 2, or 5 minutes. The anterior capsules were then stained with trypan blue and alizarin red. Photomicrographs of each capsule were taken and analyzed for LEC damage. In Group 2 (n = 8 eyes), hydrodissection was performed with 1 of the agents, followed by phacoemulsification and cortical cleanup. The LEC attachment to the anterior capsule was evaluated by histopathology. Results Anterior capsule fragments irrigated with BSS showed no LEC nuclear staining; ie, no direct toxic effect. In those irrigated with preservative-free lidocaine 1%, the LECs showed mild toxicity; some cells showed blue nuclear staining. After hydrodissection with lidocaine, the capsules were almost free of LECs; after hydrodissection with BSS, the capsules showed a normal layer of LECs attached to the anterior capsule. Conclusions Preservative-free lidocaine 1% may help diminish the amount of live LECs by facilitating cortical cleanup, by loosening the desmosomal area of cell−cell adhesion with decreased cellular adherence, or by a direct toxic effect. The use of this agent may help prevent posterior capsule opacification.