Abstract
Purpose :
To evaluate the relationship between perivascular nonperfusion area on OCT angiography (OCTA) and blood velocity on adaptive optics (AOSLO) in healthy and diabetic subjects
Methods :
This is a prospective study including healthy subjects with no diabetes mellitus (DM), subjects with DM but without diabetic retinopathy (noDR), and subjects with (nonproliferative DR (NPDR) and proliferative DR (PDR)). We analyzed AOSLO-based retinal blood velocity using semi-automated measurements of erythrocyte streak angles on AOSLO images. We used geometric perfusion deficit (GPD) analysis in OCTA to evaluate the local nonperfusion area around the same vessel, defined as the retinal area located further than 30 μm from the nearest blood vessel. We analyzed the percent area of GPD in the 100 μm perimeter around the vessels (Fig 1). We evaluated the correlation between retinal blood velocity and perivascular GPD.
Results :
We included 9 arteries in 8 eyes of healthy subjects and 18 arteries in 12 eyes with noDR and 15 arteries in 11 eyes with clinical DR (9 eyes; NPDR, 2 eyes; PDR). As shown in figure 2, in the healthy subjects, blood velocity was significantly positively correlated with periarterial GPD in the superficial plexus (SCP) (ρ = 0.773, P=0.025). On the other hand, blood velocity was significantly negatively correlated with periarterial GPD in the deep plexus (DCP) in eyes with noDR (ρ = -0.507, P = 0.032). We found no significant correlations in SCP (P=0.91) or DCP (P=0.67) in eyes with clinical DR.
Conclusions :
This study suggests that in healthy eyes, blood velocity is increased to meet the demand of the hypoxic retina. In preclinical DR eyes, failure of these autoregulatory mechanisms primarily impacts the DCP and may contribute to further capillary drop-out in DCP.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.