The role of indocyanine green angiography imaging in further differential diagnosis of patients with nAMD who are morphologically poor responders to ranibizumab in a real-life setting

Purpose To evaluate the neovascular age-related macular degeneration (nAMD) in patients who were morphologically poor responders to intravitreal ranibizumab (IVR) treatment using indocyanine green angiography (ICGA) for further investigation. Methods This was a cross-sectional, retrospective study. The patients with an initial diagnosis of nAMD who made through the clinical examination, optical coherence tomography, and fluorescein angiography imaging, and were treated with at least three monthly IVR injections that resulted with a morphological poor response, were included. ICGA was obtained from the patients and evaluated in regard to differential diagnosis of other macular diseases, which might mimic nAMD. Results The study included 132 eyes of 117 patients. The mean age was 67.4 +/- 9.4 years. After ICGA imaging, 13 eyes (9.8%) were diagnosed as true nAMD, 74 eyes (56.1%) as polypoidal choroidal vasculopathy (PCV), 35 eyes (26.5%) as chronic central serous chorioretinopathy (CSC), 3 eyes (2.3%) as retinal angiomatous proliferation (RAP), 3 eyes (2.3%) as choroidal neovascularization secondary to CSC, 2 eyes (1.5%) as adult-onset vitelliform macular dystrophy, and 2 eyes (1.5%) as drusenoid pigment epithelial detachment with vitelliform material, respectively. The duration between the initial diagnosis and the revised diagnosis was 15.6 +/- 10.5 months in the non-AMD group, and the mean injection number of these patients was 6.6 +/- 4.4. Conclusions Most of the nAMD patients who were thought to be morphologically poor responders to IVR were diagnosed as having non-AMD diseases via ICGA. A detailed differential diagnostic work-up is needed before considering these patients as poor responders.