Focal irradiation of perforating eye injuries

Abstract

Plaques constructed with 125I were used to irradiate the sites of perforating ocular injuries in rabbits. An approximate dose of 16Gy given over a period of 6 days was shown to significantly reduce intraocular cellular proliferation when irradiation was commenced within 24 hours after injury. If irradiation was delayed until day 5, this reduction in cellular proliferation and intraocular membrane formation did not occur. Smaller radiation doses of approximately 6Gy given within 24 hours post-injury and administered over 6 days also reduced the extent of cellular proliferation but was not as effective as the 16Gy dose.

Palladium-103 plaque radiation therapy for macular degeneration: results of a 7 year study

“…[33][34][35][36][37] These effects of radiation are both dose and dose rate dependent. 38 Irradiation of a macula containing classic or occult subretinal neovascularisation can directly affect angiogenesis by destroying neovascular endothelial cells and cytokine producing macrophages, or alter the regulatory genes which produce endothelial growth regulating cytokines.…”

Strontium plaque irradiation of subfoveal neovascular membranes in age-related macular degeneration

“…It is during the period of maximum cellular proliferation in the neovascularization process that endothelial cells are most sensitive to irradiation [6,10]. In contrast, mature, nonproliferating retinal and choroidal vessels are more radioresistant, and the risk of development of radiation-related retinopathy is low at doses of less than 25-30 Gy.…”

Experimental Posterior Perforating Ocular Injury in Rabbit Eyes: Effects of Radiotherapy with or without Intravitreal Cyclosporin on Vitreous Proliferation

“…In another study, Chakravarthy et al [9,11] found that a dose of 16 Gy applied with a plaque containing radioactive 125 I seeds was most effective to inhibit intraocular membrane formation. The same authors evaluated irradiated and nonirradiated vitreoretinal membranes obtained from rabbit eyes in vitro [6] .…”

“…Chakravarthy et al [9,11] had used a cobalt applicator and delivered a dose of 100 Gy to the sclera and 80 Gy to the retina and choroid and found that while 19 of 24 nonirradiated rabbit eyes developed vitreoretinal membranes, only 4 of 24 irradiated eyes developed such membranes. In another study, Chakravarthy et al [9,11] found that a dose of 16 Gy applied with a plaque containing radioactive 125 I seeds was most effective to inhibit intraocular membrane formation.…”

“…Although these problems may in part be dealt with modern vitreoretinal surgery, still a safe management protocol to be applied immediately after the initial injury to avoid the occurrence of these membranes would be a major determinant of the subsequent prognosis of the eye [1] . RT had been used for this purpose by many investigators [11,12] . However, side effects related to radiation are still a major handicap.…”