Posterior capsule opacification in mice.

OBJECTIVE To present a new model of posterior capsule opacification (PCO) in mice. METHODS An extracapsular lens extraction was performed in 28 consecutive mice. Animals were humanely killed 0 and 24 hours and 3 and 14 days after surgery. Eyes were enucleated and processed for light microscopy and immunohistochemistry. RESULTS In 20 animals (71%), the eye appeared well healed before death. In 8 animals (29%), postoperative complications were noted. All animals developed PCO 2 weeks after surgery. Immediately after extracapsular lens extraction, lens epithelial cells were present in the inner surface of the anterior capsule and at the lens bow. At 24 hours, lens epithelial cells started to migrate toward the center of the posterior capsule. At 3 days, multilayered lens epithelial cells throughout the lens capsule and capsular wrinkling were apparent. Lens fibers and Soemmerring ring formation were observed 14 days after surgery. CD45(+) and CD11b (+) macrophages were found in greater numbers 24 hours and 3 days after surgery (CD45(+), P = .04 and P<.001, respectively; and CD11b(+), P = .01 and P = .004, respectively). The number of CD45(+) cells remained statistically significantly higher (P = .04) 14 days after surgery. CONCLUSION In mice, PCO occurs following extracapsular lens extraction and is associated with low-grade but significant macrophage response. CLINICAL RELEVANCE The use of genetically modified mice to evaluate the pathogenic mechanisms of PCO and search for new therapeutic modalities to prevent or treat PCO is now possible.