Suppression of experimental corneal angiogenesis by focal X-ray irradiation

Purpose. To investigate the effect of focal X-ray irradiation on experiment al corneal angiogenesis in the rabbit. Methods. A gelatin hydrogel sheet impregnated with basic fibroblast growth factor was implanted into the corneal stroma of rabbits; this induced corne al angiogenesis. After the first sign of corneal angiogenesis was noted, th e corneal region was irradiated with a dose of 10 Gy or 20 Gy. The control rabbits received no irradiation. The eyes were examined by slitlamp biomicr oscopy and photographed, over a period of 28 days. The maximum length and t otal surface area of corneal angiogenesis were quantified by computerized i mage analysis. Results. Corneal angiogenesis was noted on day 3 following implantation of the hydrogel sheet. In the rabbits irradiated with 10 Gy, the maximum lengt h and total surface area of corneal angiogenesis were both significantly lo wer on day 4 and 7 following irradiation, compared to the respective measur ement in the controls. In the rabbits irradiated with 20 Gy, the maximum le ngth and total surface area of corneal angiogenesis were significantly lowe r between days 4 and 21, and between days 4 and 14, respectively, compared to the respective measurement in the controls. Conclusions. Focal X-ray irradiation to the corneal region suppressed corne al angiogenesis in a dose-dependent manner. Focal X-ray irradiation may be beneficial in treating ocular angiogenesis.