Evaluation of irradiated corneas using scatterometry and light and electron microscopy.

摘要

OBJECTIVE: : To determine if sterilization of donor corneas by irradiation alters optical, histologic, or ultrastructural tissue characteristics. METHODS: : Blinded assessment of 10 irradiated and 10 nonirradiated donor corneas by a scatterometer used to objectively measure backscattered corneal light. Light and electron microscopy were performed on samples from both groups. RESULTS: : The mean scattering of the nonirradiated (control) corneas was significantly lower (0.0060 +/- 0.0034, mean +/- SD) than the scattering of the irradiated corneas (0.023 +/- 0.0078; P = 0.0001). There was no statistical difference between ages, days in storage, or central corneal thickness of the 2 groups. Light microscopic evaluation revealed attenuation of the irradiated corneal epithelium with superficial stromal clefting. Transmission electron microscopy demonstrated similar fibril diameter in the nonirradiated and irradiated corneas. Although the mean interfibrillar distance was similar between the nonirradiated and irradiated groups, the interfibrillar distance in the superficial stroma was increased in the nonirradiated compared with the irradiated groups (15.4 +/- 2.4 vs. 11.8 +/- 0.98 nm; P