Long-term changes in rabbit cornea after ionizing radiation.

ABSTRACT

PURPOSE: To investigate long-term changes in the cornea after ionizing irradiation in rabbits. METHODS: Mature albino rabbits (n = 4) were unilaterally irradiated with 20 Gy of x-rays. The contralateral eye served as a control. The rabbits were examined with slit-lamp biomicroscopy for 5 years. The eyes were then enucleated for histopathologic examinations with light microscopy and transmission electron microscopy. RESULTS: On biomicroscopy, there was no corneal abnormality during the 5-year follow-up period. On histopathology, no abnormality was observed in the corneal epithelium. In the endothelium, a vacuole-like structure was recognized by light microscopy, and transmission electron microscopy revealed marked enlargement of intercellular space and anamorphosis of the nuclei. CONCLUSION: Moderate x-ray irradiation to rabbit eye did not induce any long-term damage to the corneal epithelium, but the endothelium demonstrated persistent and irreversible damage, which was observed even 5 years after irradiation.