CATT (Comparison of Age-Related Macular Degeneration Treatments Trials) was the first and largest multicenter, randomized clinical trial to compare the relative safety and efficacy of ranibizumab with bevacizumab for the treatment of neovascular AMD. Funded by the US National Eye Institute, it studied 1208 patients. Results showed that bevacizumab was noninferior to ranibizumab therapy in monthly or as-needed delivery schedules over 2 years. Mean letters gained from baseline were 8.8 letters in the ranibizumab-monthly group, 7.8 letters in the bevacizumab-monthly group, 6.7 letters in the ranibizumab as-needed group, and 5.0 letters in the bevacizumab as-needed group. Systemic adverse events were significantly greater in the bevacizumab (39.9%) than in the ranibizumab (31.7%) group, but death and arteriothrombotic events were not statistically different between the 2 drugs. At 5 years, vision gains in the first 2 years were not sustained, but 50% of eyes maintained 20/40 or better visual acuity. Geographic atrophy development or increase appeared to be stimulated by anti-VEGF therapy, with evidence that progression was related to persistence or absence of subretinal fluid.