Plaque Radiotherapy for Posterior Uveal Melanoma in 4000 Eyes: Analysis of ≥15-Letter Visual Acuity Loss in the Pre-Anti-VEGF Era

PURPOSE: To evaluate ≥15-letter visual acuity loss following plaque radiotherapy of posterior uveal melanoma (PUM) in the pre-anti-vascular endothelial growth factor (anti-VEGF) era. METHODS: We reviewed data on 4000 consecutive patients managed between 1976 and 2008 regarding patient demographics, tumor features, treatment factors, and ≥15-letter visual acuity loss over time based on tumor size category of small (0-3.0 mm thickness), medium (3.1-8.0 mm) and large (>8.0 mm). RESULTS: Of the 4000 patients, there were small (n=1011 eyes, 25%), medium (n=2445, 61%), and large (n=544, 14%) tumor categories. The PUM touched the optic disc (n=560, 14%) and/or extended under the foveola (n=644, 16%). Comparative analysis (small versus (vs.) medium vs. large PUM) showed small tumor category with demographics of younger age (p<0.01) and greater Caucasian race (p<0.05), presenting features of visual acuity ≥20/40 (p<0.01) and closer proximity to the optic disc (p<0.01) and foveola (p<0.01), and radiation treatment parameters most intense at the foveola (p<0.01). The median radiation dose to the optic disc (3100 vs. 3257 vs. 4336 centiGray [cGy], p<0.01) and the foveola (3964 vs. 3864 vs. 4598 cGy, p<0.01) was noted. Overall, ≥15-letter loss was found in 62% patients at median 16 months. By Kaplan-Meier analysis of all cases, ≥15-letter loss at 1 vs. 2 vs. 3 vs. 5 vs. 10 years was present in 30% vs. 48% vs. 60% vs. 73% vs. 82%. CONCLUSIONS: In the pre-anti-VEGF days, following treatment of PUM with plaque radiotherapy, visual acuity showed ≥15-letter loss in 62% of patients at median 16 months.