Natural history of radiation papillopathy after proton beam irradiation of parapapillary melanoma.

Abstract

To evaluate the natural history of radiation papillopathy after proton beam irradiation of parapapillary choroidal melanoma. Noncomparative case series. Ninety-three eyes of 93 patients. Retrospective chart review of patients with choroidal melanoma within 0 to 1 disc diameter (DD) of the optic nerve and at least 2 DD away from the fovea treated with proton beam irradiation. Rates of papillopathy, visual loss, and visual improvement. Sixty-eight percent of patients developed papillopathy a median of 1.5 years (17.7 months) after radiation. Among patients who developed papillopathy, 5-year rates of vision retention were 42% for counting fingers or better and 23% for 20/200 or better. At 5 years after the onset of papillopathy, 31% of patients had spontaneous visual improvement of 3 or more lines compared with the time of papillopathy diagnosis. Even in eyes receiving high doses of radiation to the optic nerve for treatment of intraocular tumors, approximately two thirds of patients develop radiation papillopathy. After the development of papillopathy, 42% of eyes retain useful vision and one third of eyes have significant spontaneous visual improvement over 5 years. The natural history of radiation papillopathy may be more favorable than previously assumed, and therefore treatments for this condition must be compared with an appropriate control group.