Evaluation of the optic disk in diabetic patients using optical coherence tomography angiography

Purpose The present study evaluated optic disk perfusion using optical coherence tomography angiography (OCT-A) in diabetic patients. Patients and methods This is a cross-sectional noninterventional study that was conducted on 50 eyes of 50 diabetic patients of type 2 diabetes mellitus and 10 normal eyes. Eyes were divided in to four groups. Group 1 included 10 eyes of 10 diabetic patients without diabetic retinopathy (DR); group 2 included 20 eyes with nonproliferative DR; group 3 included 20 eyes with proliferative DR; and group 4 included 10 eyes of five healthy normal individuals as control. Results OCT-A detected a significant decrease in vascular density index (VDI) at the superficial papillary, deep papillary, and choriocapillaris levels in groups with DR (2,3) compared with groups without DR (1,4) with a P value of 0.001. The VDI was significantly less in group 3 than in group 2 at all levels (superficial papillary, deep papillary, and choriocapillaris) with P values of 0.001 and 0.013, 0.001, respectively. The VDI of group 1 was significantly lower than group 4 at the superficial and deep papillary levels with P values of 0.001 and 0.031, respectively. In the four groups, the higher VDI of all groups at the superficial papillary, deep papillary, and choriocapillaris levels correlate with better visual acuity (best corrected visual acuity) by logMAR and lower levels of glycated hemoglobin. Conclusion OCT-A is an important diagnostic tool that can detect early microvascular changes in the optic disk in diabetic patients even before clinically detected DR changes.