Visual results following cobalt plaque radiotherapy for posterior uveal melanomas.

Visual results of cobalt plaque radiotherapy on the eyes of 77 patients with posterior uveal melanoma in one eye and pretreatment visual acuity of 20/25 or better in both eyes were analyzed using actuarial methods. The study demonstrated that eyes receiving a radiation dose in excess of 5,000 rad to the fovea and/or optic disc commonly lose a substantial amount of vision within 2 to 3 years. It also showed that eyes treated by cobalt plaque radiotherapy for a large posterior uveal melanoma are more likely to suffer profound visual loss than those treated for a medium or small melanoma. The predominant cause of severe visual loss in these patients appeared to be foveal radiation retinopathy.