Plaque radiotherapy for uveal melanoma - Long-term visual outcome in 1106 consecutive patients

Objective: To identify clinical predictive factors for visual outcome in a large series of patients who underwent plaque radiotherapy for uveal melano ma. Design: Clinical factors, including patient data, tumor features, and radia tion variables, were analyzed for their impact on visual acuity using Cox p roportional hazards regression models. Participants: Patients with uveal melanoma and initial visual acuity of 20/ 100 or better in the affected eye who were treated with plaque radiotherapy between July 1976 and June 1992. Main Outcome Measures: Two end points were used to evaluate posttreatment v isual acuity: (1) final visual acuity (good [20/20-20/100] vs poor [20/200 to no light perception]) and (2) loss of visual acuity (minimal [<5 lines S nellen visual acuity] vs moderate [greater than or equal to 5 lines Snellen visual acuity]). Results: Of 1300 consecutive patients with uveal melanoma treated by plaque radiotherapy, 1106 had a visual acuity of 20/100 or better at the time of treatment. In this group, poor visual, acuity was found in 34% at 5 years a nd 68% at 10 years of follow-up. From multivariable analysis, clinical fact ors that best predicted poor visual acuity were increasing tumor thickness, proximity to foveola of less than 5 mm, notched plaque shape, tumor recurr ence, patient age 60 years or older, subretinal fluid, cobalt isotope, ante rior tumor margin posterior to equator, and worse initial visual acuity. Mo derate loss of visual acuity of 5 Snellen lines or more was found in 33% at . 5 years and 69% at 10 years of follow-up. From multivariable analysis, cl inical factors that best predicted moderate visual acuity loss included inc reasing tumor thickness, worse initial visual acuity, notched plaque shape, tumor recurrence, proximity to foveola of less than 5 mm, patient age of 6 0 years or older, subretinal fluid, and diabetes mellitus or hypertension. When analyzing visual outcome with regard to tumor thickness, ultimate poor visual acuity of 20/200 or worse at 5 years was found in 24% with a small melanoma (less than or equal to 3.0 mm), 30% with a medium melanoma (3.1-8. 0 mm), and 64% with a large melanoma (>8.0 mm). When analyzing visual outco me with regard to tumor proximity to visually important structures, tumors less than 5 mm from the optic disc or foveola demonstrated poor visual acui ty in 35% at 5 years, whereas those 5 mm or more from the optic disc and fo veola showed poor visual acuity in 25% at 5 years. Conclusions: Ultimate visual acuity after plaque radiotherapy for uveal mel anoma depends on many factors, including patient age and general health, in itial visual acuity, tumor location and size, subretinal fluid, radioactive isotope, and final tumor control. At 10 years' follow-up, 68% of patients demonstrate poor visual acuity. Visual acuity is most effectively preserved in eyes with small tumors outside a radius of 5 mm from the optic disc and foveola.