Cellular Fibronectin, but not Collagens, Disappears in the Central Posterior Capsules During Healing After Lens Extraction and IOL Implantation in Rabbits

Abstract

Purpose: To investigate the nature of capsular opacification after cataract-intraocular lens (IOL) surgery in rabbit eyes, we immunohistochemically located extracellular matrix components in lens capsules after the surgery using light microscopy. The study was conducted also to compare the extracellular matrix components in rabbit capsules with those previously reported in the human eye. Methods: Twenty-seven eyes of 17 Japanese albino rabbits were lensectomized by phacoemulsification, and IOLs were implanted. Using immunohistochemical methods, the lens capsules were examined immediately after surgery, and 1, 2, 4, and 8 weeks after surgery. Results: In all cases at each time point, the edge of the anterior capsulotomy had contracted and was found to adhere to the inner surface of the posterior capsule, with both IOL haptics remaining in the capsular bag. Collagen types I and III were detected around the adhesion between the anterior capsulotomy edge and posterior capsule during all stages of healing and also observed on the central posterior capsules 1 or more weeks after surgery. Immunoreactivity for cellular fibronectin was seen around the adhesion between the anterior capsulotomy edge and posterior capsule during all stages of healing. It was also detected on the posterior capsules 2 and 4 weeks after surgery, but disappeared 8 weeks after surgery. Conclusion: Extracellular matrix components such as collagen types I and III and cellular fibronectin were expressed inside the residual lens capsular bag. Cellular fibronectin may play a role in the early wound healing process in the postoperative posterior capsule because the immunoreactivity in the central posterior capsule disappears in the later phase of healing.