Histopathological examination of two cases of anterior staphyloma associated with Peters' anomaly and persistent hyperplastic primary vitreous.

AIMS To clarify the developmental mechanism and critical period for the uncommon complex of Peters' anomaly and persistent hyperplastic primary vitreous (PHPV). METHODS Two eyes with Peters' anomaly and PHPV were histologically examined by serial section. One eye was enucleated at age 7 months (case 1) and the other at age 4 months (case 2) owing to severe anterior staphyloma. RESULTS In both eyes, defects in the endothelium, Descemet's membrane, and posterior stroma were observed in the central cornea, and the degenerative lens adhered to the posterior surface of the defective corneal stroma. Also, in both eyes, the anterior chamber space was not formed and the undifferentiated iris stroma adhered to the posterior surface of the peripheral cornea. Mesenchymal tissue containing melanocytes was observed behind the degenerative lens, and the pigment epithelium was absent at the lower nasal side of the ciliary body in case 1. In case 2, mesenchymal tissue containing scattered melanocytes in the vitreous cavity was seen on the posterior retina. Based on the histological findings, both cases were diagnosed as Peters' anomaly caused by the faulty separation of the lens vesicle, PHPV, maldevelopment of the iris and ciliary body, and goniodysgenesis. CONCLUSION Migratory disorders of neural crest cells from 4 to 7 weeks of gestation may be responsible for various ocular anomalies including Peters' anomaly and PHPV, as observed in these cases.