[Effects of fractionated irradiation of the rabbit eye. A histopathologic study]

The effect of fractionated 300 kV roentgen radiation on different sections of the eye (cornea, ciliary body, retina, and choroid) was investigated in 36 rabbits. Four groups of nine animals each were exposed to 21, 30, 36, and 45 Gy in constant fractions of 5 x 3 Gy per week. After three weeks, three months, and six months three animals from each group were killed. Both eyeballs, the eyelids, and the lacrimal glands were removed, fixed, and embedded in paraffin. The 15 sections made of each specimen were stained according to PAS and HE. The application of total doses of 21, 30, and 36 Gy did not lead to any histopathologically discernible alterations. Only in one animal was an ulcerating keratitis seen to develop within three months in response to a dose of 45 Gy. In the same group, a perilimbic conjunctival inflammation developed in three animals after six months and in two after three months. All animals which had received doses of 45 Gy and were examined after six months were found to have a vacuolic swelling of the ciliary epithelium. In one animal which had received a dose of 45 Gy a myointimal proliferation of a ciliary artery was seen three months after termination of the treatment.