A morphological study of the foveal avascular zone in patients with diabetes mellitus using optical coherence tomography angiography.

PURPOSE

To investigate the area and radius of the foveal avascular zone (FAZ) in patients with diabetes mellitus (DM) using optical coherence tomography (OCT) angiography.

METHODS

Sixty-five patients with DM (113 eyes) and 62 healthy controls (85 eyes) were included in the study. All of the participants underwent examination with OCT angiography. The vertical radius (VR), horizontal radius (HR) and area of the FAZ were measured.

RESULTS

The differences in HR, VR and area between the control and DM groups were statistically significant (p = 0.01, 0.00 and 0.00, respectively). There were no statistically significant differences between the control group and the no-diabetic retinopathy (DR) group in HR or VR (p = 0.07 and 0.08, respectively), but there was a statistically significant difference in area (p = 0.04). The size of the FAZ was greater in patients with DR compared to the control group. The differences in HR, VR and area were statistically significant (p = 0.01, 0.00 and 0.00, respectively). In addition, the clinically significant macular oedema (CSME) group also had a larger FAZ area than the non-CSME group (p = 0.02).

CONCLUSIONS

Patients with DM had a larger FAZ, and patients with more severely damaged retinas had a much larger FAZ. OCT angiography is a new convenient and noninvasive method for studying the FAZ. This novel examination will yield considerable amounts of data that cannot be obtained using previous research methods.