INCIDENCE AND CAUSES OF VISION LOSS DURING AFLIBERCEPT TREATMENT FOR NEOVASCULAR AGE-RELATED MACULAR DEGENERATION One-Year Follow-up MASAYUKI HATA, MD,* AKIO OISHI, MD, PHD,* KENJI YAMASHIRO, MD, PHD,* SOTARO OOTO, MD, PHD,* HIROSHI TAMURA, MD, PHD,* HIDEO NAKANISHI, MD, PHD,* NAOKO UEDA-ARAKAWA, MD,* YUMIKO AKAGI-KURASHIGE, MD, PHD,* YOSHIMASA KURODA, MD,* AYAKO TAKAHASHI, MD,* AKITAKA TSUJIKAWA, MD, PHD,† NAGAHISA YOSHIMURA, MD, PHD* Purpose: To investigate the incidence rate, risk factors, and final outcomes of patients with age-related macular degeneration (AMD) who have experienced vision loss despite periodic aflibercept treatment. Methods: Subjects with treatment-naive AMD were prospectively recruited and treated with three monthly injections followed by two monthly injections of aflibercept. The incidence rate and risk factors of more than two lines of vision loss at any visit were investigated. Results: We included 196 eyes of 196 patients. Vision loss was observed in 16 patients (8.2%). Eleven of 16 patients developed vision loss during the initial 3 months (68.8%). Vision loss remained in 11 eyes (68.8%) at the final visit. The maximum pigment epithelium detachment (PED) height (odds ratio = 1.46 for a 100-mm increase in the PED height) and disruption of the external limiting membrane (odds ratio = 4.45) were identified as risk factors for developing vision loss on logistic regression analysis. Conclusion: The incidence rate of vision loss during aflibercept treatment was relatively low. Identifying high-risk patients, those with a high PED height and disruption of the external limiting membrane, would be helpful in ensuring appropriate informed consent before treatment. Further studies are needed to establish optimal treatment for these patients. RETINA 37:1320–1328, 2017 A ge-related macular degeneration (AMD), which can be divided into dry and wet forms, is a leading cause of visual impairment, especially in developed countries. Although visual impairment progresses gradually in dry AMD, visual decline can be rapid in wet/exudative AMD because of choroidal neovas- cularization (CNV) and subsequent hemorrhage or exudative changes. 1 The treatment of wet/exudative AMD was unsatisfactory until a decade ago, but devel- opment of antivascular endothelial growth factor (VEGF) drugs dramatically changed this outcome. Two pivotal randomized studies have clearly shown that the monthly intravitreal injections of ranibizumab are effective in improving vision. 2,3 Aflibercept is another anti-VEGF drug, which has a higher affinity to VEGF, a longer half-life, and the capability of inhibiting the placental growth factor. 4 These factors can theoretically be advantageous in the treatment of choroidal neovascularization. The VIEW I/II study showed that 3 monthly injections followed by bimonthly injections are not inferior to monthly injections of ranibizumab in terms of visual gain within 52 or 96 weeks. 5,6 Although anti-VEGF drugs dramatically improve the overall visual outcome, some patients still lose vision despite intensive treatment with these drugs. 7,8 Considering high expectation of patients, they are informed that regular injection can achieve more than 1320