Type 1 Choroidal Neovascularization Lesion Size: Indocyanine Green Angiography Versus Optical Coherence Tomography Angiography

To evaluate the size of type 1 choroidal neovascularization (CNV) in neovascular AMD by optical coherence tomography angiography (OCTA) and to compare with indocyanine green angiography (ICGA). Patients diagnosed type 1 CNV underwent multimodal imaging by fluorescein angiography (FA), ICGA, spectral-domain (SD)-OCT, and OCTA. Lesion size was measured both on OCTA at the choriocapillaris level with "select area" and "vessel area" functions, incorporated in AngioVue software and on ICGA at intermediate and late phases, by two masked independent readers. Nineteen eyes of 17 patients (mean age 80.6 ± 8.36) were included in the analysis. Mean visual acuity was 0.2 logMAR. All OCTA revealed a high flow neovascular network in the choriocapillaris segmentation. On OCTA, interclass correlation between readers 1 and 2 was 0.96 (95% confidence interval [CI] 0.94-0.99) for select area and 0.97 (95% CI 0.96-0.99) for vessel area. The difference between lesion size in OCTA versus ICGA was detected in all eyes and it was statistically significant for both readers (P < 0.05). Optical coherence tomography angiography provides both quantitative and qualitative information on type 1 CNV and appears as a new reproducible way to evaluate CNV area and vessels area. Type 1 CNV lesion size in the choriocapillaris segmentation of OCTA and ICGA intermediate and late phases revealed that the OCTA size is significantly smaller than the ICGA size. This supports the idea that OCTA could be considered for evaluation of the neovascular lesion and for evaluation of therapeutic responses.