Three-year follow-up of a pilot study of ranibizumab combined with proton beam irradiation as treatment for exudative age-related macular degeneration

BACKGROUND: To investigate the safety and tolerability of ranibizumab combined with proton beam irradiation in treating exudative age-related macular degeneration. METHODS: Six eyes (6 subjects) with exudative age-related macular degeneration (4 newly diagnosed; 2 previous treated with ranibizumab) were treated with 4 monthly ranibizumab and 24 GyE proton beam irradiation (2 fractions, 24 hours apart) and seen monthly thereafter and retreated with ranibizumab for decrease in best-corrected visual acuity of ≥2 lines, new macular hemorrhage or fluid noted on optical coherence tomography. RESULTS: Follow-up ranged from 12 months to 36 months (mean, 28 months). Baseline best-corrected visual acuity ranged from 20/40 to 20/250. Final best-corrected visual acuity ranged from 20/25 to 20/400. No radiation retinopathy was noted in any eye. Calculated radiation distribution dose curves indicate that ≤10% of retina received ≥90% of radiation dose in all eyes. Two subjects lost ≥3 lines of best-corrected visual acuity during follow-up, 1 subject in both eyes from enlarging geographic atrophy and the other from worsening fibrovascular pigment epithelial detachment, which was refractory to multiple ranibizumab treatments before enrollment. Among 4 eyes with newly diagnosed exudative age-related macular degeneration, 3 had no fluid on optical coherence tomography at month 12 without further treatment. CONCLUSION: No safety concerns were noted after 3 years in eyes with exudative age-related macular degeneration treated with ranibizumab combined with proton beam irradiation in this small pilot study. A larger randomized prospective study is under way to further evaluate this combination therapy.