Histopathological examination of congenital corneal staphyloma and prognosis after penetrating keratoplasty

The aim of this study was to investigate the histopathological manifestations of congenital corneal staphyloma accompanied by anterior segment dysgenesis and evaluate the prognosis after penetrating keratoplasty with an ultralarge button graft. We retrospectively studied 8 pediatric patients with large congenital corneal staphylomas in the Department of Ophthalmology of Peking University Third Hospital, China, between September 2014 and December 2018. All patients underwent penetrating keratoplasty with ultralarge button grafts, as well as additional operations according to the abnormality of each eye. Pathological investigations of all samples obtained during penetrating keratoplasty were performed with hematoxylin and eosin staining. The main clinical characteristic of congenital corneal staphyloma was an extremely opaque and ectatic cornea. Histopathological examination showed abnormal corneal epithelia and stroma and an absence of Bowman membrane, Descemet membrane, and the endothelium. Different severities of anterior segment dysgenesis, presenting as various histopathological manifestations, were observed in all cases. Several postoperative complications occurred after penetrating keratoplasty in some of the patients; however, the complications were discovered and treated accordingly in a timely manner. Six patients achieved good visual outcomes and a satisfactory cosmetic appearance after penetrating keratoplasty. One patient eventually lost the transparency of the button because of corneal neovascularization, and 1 patient lost visual function because of retinal detachment. Congenital corneal staphyloma combined with anterior segment dysgenesis can exhibit various manifestations on histopathological examination. Penetrating keratoplasty with an ultralarge button graft seems to be a suitable treatment for congenital corneal staphyloma to obtain good functional and aesthetic prognoses.