histopathology of recipient corneal buttons after penetrating keratoplasty

purpose: to report the histopathological diagnoses of recipient corneal buttons in patients undergoing penetrating keratoplasty. methods: in this observational case series, all recipient corneal specimens sent to the ophthalmic pathology laboratory of the eye bank of iran between 2004 and 2007 underwent histopathologic examination. results: overall, 315 corneal specimens were evaluated. histopathologic diagnoses included keratoconus (27.0%), corneal dystrophies (23.5%), acquired corneal endothelial decompensation (13.3%), nonspecific corneal scars and degenerations (11.4%), keratitis (10.8%), mustard gas keratopathy (8.0%), combined dystrophy and keratoconus (1.6%), post-keratorefractive keratectasia (1.6%), chemical burn-induced keratopathy (1.3%) and other causes (1.6%). in keratoconic corneas, breaks in bowmans’ layer were evident in all cases and hydrops was diagnosed in 17.6%. the most common corneal dystrophy was macular corneal dystrophy (35.0%) followed by fuchs’ endothelial dystrophy (26.25%). in cases with keratitis, causative microorganisms were found in 35.2%. histopathologic findings in mustard gas keratopathy included loss of keratocytes, thickening of epithelial basement membrane, foci of acute and chronic inflammation and secondary degenerative changes; the former two were the most common features. conclusion: to our knowledge, this is the first report on histopathologic evaluation of recipient corneas in iran. keratoconus, corneal dystrophies, acquired endothelial decompensation, nonspecific corneal scars and degenerations, keratitis and mustard gas keratopathy were predominant histopathologic diagnoses. loss of keratocytes and thickening of epithelial basement membrane were the most common histopathologic findings in mustard gas keratopathy. breaks in bowmans' layer were found in all keratoconic corneal buttons.