| dc.description | PURPOSE. To evaluate whether retinal capillary nonperfusion is found predominantly adjacent
to arteries or veins in eyes with diabetic retinopathy (DR).
METHODS. Sixty-three eyes from 44 patients with proliferative DR (PDR) or non-PDR (NPDR)
were included. Images (12 3 12-mm) foveal-centered optical coherence tomography (OCT)
angiography (OCTA) images were taken using the Zeiss Plex Elite 9000. In 37 eyes, widefield
montages with five fixation points were also obtained. A semiautomatic algorithm that detects
nonperfusion in full-retina OCT slabs was developed, and the percentages of capillary
nonperfusion within the total image area were calculated. Retinal arteries and veins were
manually traced. Based on the shortest distance, nonperfusion pixels were labeled as either
arterial-side or venous-side. Arterial-adjacent and venous-adjacent nonperfusion and the A/V
ratio (arterial-adjacent nonperfusion divided by venous-adjacent nonperfusion) were
quantified.
RESULTS. Twenty-two eyes with moderate NPDR, 16 eyes with severe NPDR, and 25 eyes with
PDR were scanned. Total nonperfusion area in PDR (median: 8.93%) was greater than in
moderate NPDR (3.49%, P < 0.01). Arterial-adjacent nonperfusion was greater than venousadjacent
nonperfusion for all stages of DR (P < 0.001). The median A/V ratios were 1.93 in
moderate NPDR, 1.84 in severe NPDR, and 1.78 in PDR. The A/V ratio was negatively
correlated with the total nonperfusion area (r ?? 0.600, P < 0.0001). The results from the
widefield montages showed similar patterns.
CONCLUSIONS. OCTA images with arteries and veins traced allowed us to estimate the
nonperfusion distribution. In DR, smaller nonperfusion tends to be arterial-adjacent, while
larger nonperfusion tends toward veins. | |
