Dimensions of the foveal avascular zone using the Heidelberg retinal angiogram-2 in normal eyes

PURPOSE: The purpose was to study the dimensions of the foveal avascular zone (FAZ) using Heidelberg Retinal Angiogram-2 (HRA-2; Heidelberg Engineering GmBH, Dossenheim, Germany). MATERIALS AND METHODS: An observational study of the FAZ area and circumference was done with fundus fluorescein angiography (FFA) using HRA-2 in 31 normal individuals. The FAZ was studied using both contrast-adjusted and nonadjusted methods. Contrast adjustment was done to obtain better visualization of the finer capillaries around the fovea enabling more precise measurements of the FAZ in normal eyes. RESULTS: The mean area of the FAZ calculated by the contrast-adjusted method was 0.2753 mm(2) (±0.074) and the mean circumference was 2.22 mm (±0.048). By the conventional method, the area and circumference of the FAZ were 0.6241 mm(2) (±0.177) and 3.23 mm (±0.454), respectively. CONCLUSION: The measurements of area and circumference of FAZ using contrast-adjusted methods were significantly smaller than the conventional method.