Anterior capsular plaque in congenital cataract: occurrence, morphology, immunofluorescence, and ultrastructure.

PURPOSE To study occurrence, morphology, immunofluorescence, and ultrastructural features of congenital anterior capsular plaque (ACP) obtained from pediatric eyes undergoing cataract surgery. METHODS Two hundred sixty consecutive pediatric eyes undergoing congenital cataract surgery were enrolled in the present study. Anterior lens epithelium from cataract without ACP and with ACP was collected. Wholemounts of lens epithelium were stained with hematoxylin-eosin. Five-micrometer-thick sections of large ACPs were subjected to immunofluorescence localization of collagen type I, collagen type IV, alpha-smooth muscle actin (alpha SMA), and alpha A-crystallin. Ultrathin sections were studied by transmission electron microscope. RESULTS The overall occurrence of ACP in pediatric eyes undergoing congenital cataract surgery was 11.5%. The occurrence of ACP was highest in mature cataract followed by nuclear, lamellar, and mixed cataract. The wholemount of anterior lens epithelium revealed nonplaque and plaque region or ACP. Depending on the area, ACPs can be classified as small, medium, and large. The extracellular matrix of ACP was fibrous and amorphous. It was rich in collagen type I. The cells of the ACP were surrounded by a network of collagen type IV and were positive for alpha SMA and alpha A-crystallin. The cells of the ACP were rich in rough endoplasmic reticulum and mitochondria. CONCLUSIONS The occurrence of ACP in pediatric eyes undergoing cataract surgery for congenital cataract was 11.5%. ACP was more associated with mature cataract. Epithelial mesenchymal transdifferentiation of lens epithelial cells may be involved in the development of congenital ACP.