Abstract
Purpose :
We used geometric perfusion deficit (GPD) analysis in OCT angiography (OCTA) to test the hypothesis that early nonperfusion in patients with diabetes mellitus (DM) without diabetic retinopathy (DR) localizes to the deep capillaries near larger vessels.
Methods :
After averaging multiple OCTA scans (average 6.7 ± 1.0 scans), we used a semi-automated method to measure GPD, defined as the retinal area located further than 30 μm from the nearest blood vessel, and compared healthy subjects to patients with DM without DR. In the superficial capillary plexus (SCP), deep (DCP) and full retina, we analyzed percent area of GPD in the whole scan as well as in the 100 μm area around arterioles (periarteriolar space), the 100 μm area around venules (perivenular space) and in the area greater than 100 μm from the nearest arteriole or venule (capillary space).
Results :
Our initial analysis included 11 eyes of 11 healthy subjects (6 females; age 39.9 ± 11.7 years) and 11 eyes of 11 patients with DM without clinical DR (7 females; age 46.9 ± 16.0 years). The GPD in the DCP was significantly greater in patients with DM without DR compared to healthy subjects (4.0% ± 1.1% versus 3.2% ± 0.8%, respectively; p=0.030), but not in the SCP or full retina (p=0.371 and p=0.094, respectively). Perivenular GPD in the DCP showed the greatest difference (3.0% ± 1.1% in DM versus 2.2% ± 0.7% in healthy; p=0.028), while the periarteriolar and capillary spaces showed no significant difference (p=0.073 and p=0.151, respectively).
Conclusions :
We found that perfusion deficits were increased most prominently in the deep capillaries near venules in patients with DM without clinical DR compared to healthy controls. This study suggests that in the macula, early capillary dysfunction in diabetes may preferentially occur in the perivenular compartment of deep capillary plexus.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.