Ahram Mineral Water-Induced Sulfate Keratopathy: Histopathologic, Electron Microscopic, and Confocal Scan Features

Abstract

To characterize histopathologic, electron microscopic, and confocal scan features of Ahram mineral water (AMW)-induced keratopathy in cadaver corneas. Seven cadaver globes were examined, 5 of which were exposed to AMW from the corneal side for different durations (30 seconds and 3, 15, 30, and 60 minutes) and the other 2 were considered as control. After performing confocal scan on each cornea, we excised the corneoscleral rim and sent it for histopathologic evaluation. Scanning electron microscopic and transmission electron microscopic examinations were performed on the cornea exposed to AMW for 60 minutes. Depending on the time of exposure, the confocal scan features varied from intraepithelial high-contrast deposits to subepithelial bulla formation. The histopathologic features ranged from diffuse intracytoplasmic sulfur deposits to subepithelial bulla formation. Scanning electron microscopic examination disclosed rather diffuse irregular bright deposits of high sulfur content over the surface epithelium and together with focal cellular destruction and micro-hole formation in the case with 60-minute exposure. On transmission electron microscopy, electron-lucent bulky deposits were found underneath the basal epithelial cells and between their basement membrane and Bowman layer. Confocal scan of the control corneas disclosed nonspecific anterior stromal haze and Descemet folds, with no evidence of intraepithelial deposits. No pathologic finding was noted on histopathologic examination of the control corneas. AMW induces sulfate keratopathy of mainly anterior corneal involvement and with various histopathologic, confocal microscopic, and electron microscopic features even with short-time exposure.