Assessment of foveal avascular zone in diabetic retinopathy

ABSTRACT

Purpose: To evaluate the measures of foveal avascular zone [PAZ] in diabetic population and compare it with nondiabetic subjects. Patients and The dimensions of FAZ were done in fluorescein angiogrms in 30 diabetic patients and 20 nondiabetic controls. The longest diameter, the perpendicular diameter, the mean diameter, the circumference, and the area of FAZ were measured and compared with level of fluorescein leakage and capillary nonperfusion the median values for longest diameter, mean diameter, and circumference were significantly greater in diabetic group than in control group. Longest diameters > 1.0 mm were found almost exclusively in eyes with proliferative diabetic retinopathy. The FAZ dimensions and presence of proliferative diabetic retinopathy were strongly positively correlated with capillary nonperfusion not with fluorescein leakage. Diabetic retinopathy is characterized by an irregular large FAZ. Retinal capillary occlusion is the cause of FAZ enlargement in diabetic retinopathy. It would be better to specify laser treatment guidelines in terms of the actual distance from the center of FAZ not FAZ margin guidelines, since the dimensions of normal FAZ are so variable from subject to subject