Verma A, Maram J, Alagorie AR, et al. - Researchers conducted this prospective observational study to analyze the peripheral extent of choroidal circulation using ultra-widefield (UWF) indocyanine green angiography (ICGA) in healthy eyes. Using the Optos California (Optos, Dunfermline, United Kingdom), UWF ICGA images of 55 eyes of 36 healthy individuals were captured. To locate the peripheral extent of the visible choroidal circulation, images were analyzed and the boundary was marked in ImageJ (v1.52). Data reported that the mean area of the peripheral extent was estimated to be 893.2 mm² (95% CI: 844.2 to 942.3 mm²). Multiple regression analysis showed no connection with age, gender, axial length, or ethnicity. Excellent inter-grader reproducibility was observed, with intraclass correlation coefficients of 0.95 for distance and 0.99 for area measurements. Using UWF ICGA, the peripheral choroidal boundary can be defined. To understand the impact of the disease on the choroidal vasculature, knowledge of the normal extent and its variability is important.