Abstract
Abstract: :
Purpose: To describe a new model of posterior capsule opacification (PCO) in rodents Methods: An extracapsular lens extraction (ECLE), using continuous curvilinear capsulorrhexis and hydrodissection, was performed in 42 consecutive Brown-Norway rats. Animals were sacrificed at 0, 6, 24 hours and 3, 7 and 14 days postoperatively. Eyes were enucleated and processed for light microscopy and immunohistochemistry. Results: In 34 animals (81%) the operated eye appeared well healed before sacrifice, with clear cornea and well-formed anterior chamber. PCO was clinically evident three days after ECLE and was present in all animals at two weeks. Immediately after ECLE, LEC were present in the inner surface of the anterior capsule and lens bow. Twenty-four hours postoperatively, LEC started to migrate towards the center of the posterior capsule. At three days multilayered LEC were present throughout the lens capsule. Capsular wrinkling was apparent. Lens fibers and Soemmerring's ring were observed in all animals 14 days postoperatively. Activated macrophages were found in greater numbers at 3 and 14 days postoperatively (p < 0.05), when proliferation and migration of LEC appeared to be greatest and lens fiber differentiation was evident, respectively. Conclusion: In rodents PCO occurs following ECLE and is associated with low grade inflammation, mostly of mononuclear macrophages. This model appears to be valuable to study the sequence of events that lead to PCO following cataract surgery, and the extracellular matrix cues which promote lens fiber differentiation.
Keywords: posterior capsular opacification (PCO) • animal model • inflammation