Abstract
Purpose :
To explore the relationship between MA wall characteristics on AOSLO imaging and MA size, perfusion parameters and fluorescein leakage.
Methods :
An observational study enrolled adults with diabetes. Macular MAs were imaged with AOSLO multiply scattered light and confocal techniques. Standard deviation perfusion maps were generated from 75-frame videos (30 frames per second, 2°x2° area). MA confocal images were graded for wall hyperreflectivity (WH). Wall deformability (WD: apparent deformation of the vascular wall due to adjacent blood flow), cross-sectional area, perfusion percentage, presence of intraluminal clot and morphology were graded on both multiply scattered light and confocal images. AOSLO images were registered to 200° color fundus photographs. Leakage was assessed using fluorescein angiography.
Results :
AOSLO imaging was performed of 174 MAs from 31 eyes of 21 participants. Mean age was 43.4 years, diabetes duration 21.5 years, with 67% type 1 and 38% female. Range of DR severity was: mild NPDR 45% (N=14), moderate NPDR 29% (9), severe NPDR 19% (6) and PDR 6% (2). WH was more frequently present in MAs that were larger (mean area: 5,445 vs 3,577 µm2, p<0.0001), with less perfusion (% perfused: 56.1% vs 71.9%, p=0.0002), associated with clot (clot present: 55.9% vs 25.2%, p<0.0001) and without WD (WD absent: 13.6% vs 45.2%, p=0.0002). Although fluorescein leakage was more likely in MAs with WH, this was not statistically significant (64.3% vs 43.6%, p=0.07). In contrast, the presence of WD was associated with MAs that were smaller (area: 3,469 vs 4,601µm2, p<0.0001), with more perfusion (% perfused: 79.6% vs 59.7%, p<0.0001), and less likelihood of clot (clot present: 20.0% vs 43.9%, p=0.002). WD was not related to fluorescein leakage. Neither WH nor WD was significantly associated with MA morphology, overall DR severity, or participant age or gender.
Conclusions :
AOSLO allows differentiation of MAs by vascular wall characteristics of hyperreflectivity and deformability, which are both strongly associated with MA size and perfusion status. Given these associations, hyperreflectivity may be characteristic of more mature MAs, whereas deformability may be present in earlier stage lesions. Future studies will explore effects on MA development, resolution, and associated hemorrhage in the diabetic eye.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.