Histopathological Features in a Case of Peters' Anomaly with Acquired Corneal Staphyloma

We report a case of corneal staphyloma histologically diagnosed as caused by Peters' anomaly. A 62-year-old male had a protruding opaque vascularized cornea that began to bulge from six months ago in the right eye. Since his right eye was blind and he wanted us to remove the eyeball for cosmetic improvement, we enucleated the affected eye. The enucleated tissue was fixed in formalin and embedded in paraffin for histological examination. Hematoxylin and eosin staining showed that the cornea lacked the posterior part of the corneal stroma and Descemet's membrane in the central region and the entire corneal endothelium. The corneal epithelium was keratinized. Collagen type I was strongly positive in peripheral cornea and weakly in protruding stroma. The cells labeled by antibodies against αSMA were scattered in the entire corneal stroma. As judged by the histological findings, the eye with the central corneal staphyloma was diagnosed as Peters' anomaly.