Iris melanocytes on the posterior corneal surface in congenital glaucoma. A clinicopathological case report

The histological and ultrastructural pathology of two corneas that were removed from an infant with congenital glaucoma prior to keratoplasty is described. Clinically, the glaucoma was suspected to be due to an inapparent congenital viral infection, although there was no serological proof. Macroscopic and light microscopic examination of the posterior corneal surface revealed an irregular network of heavily pigmented cells that were overlying an incomplete endothelium and a grossly thickened Descemet's membrane. By scanning and transmission electron microscopy, these melanin-laden cells exhibited the features of iris stromal melanocytes. No evidence of viral infection could be found. The possible mechanisms leading to this unusual morphology are considered and will be discussed in relation to current theories on the etiology of congenital glaucoma.