Abstract
Purpose :
To compare the number of MA in early versus late phase FA with counts from SS-OCTA images in subjects with diabetic retinopathy (DR).
Methods :
This was a retrospective, observational study. Subjects were selected based on the availability of the images and the quality of the available images. The FA images were obtained from Spectralis® OCT (Heidelberg Engineering, Germany) and OCTA images were obtained from SS-OCTA (PlexEliteTM, Carl Zeiss Meditec, Dublin, CA). Early and late phase FA were defined as 30 seconds (range: 30-35 seconds) and 3 minutes (range: 2.71-3.46 minutes) during the transit respectively. MA counts from 6×6 mm OCTA scans were compared with counts from the corresponding area of early and late phase FA images. Statistical analysis was performed using ANOVA and a paired student t-test.
Results :
Four eyes of 4 subjects were included in the study. The mean (± SD) age of the subjects was 56.5 (± 8.4) years. One of the subjects had proliferative DR and three had severe non-proliferative DR. The MA count in each eye on OCTA was 23, 11, 30 and 95 (Mean ± SD = 39.8 ± 32.6). The MA count during early and late phase FA for the same eyes was 41, 21, 52 and 140 (Mean ± SD = 63.5 ± 45.5) and 46, 27, 54 and 153 (Mean ± SD = 70 ± 48.9), respectively. There were significantly more MA detected in late phase FA than in OCTA (P=0.04). The difference in MA detected in early phase FA and OCTA did not reach significance (P=0.49).
Conclusions :
The number of MAs counted on OCTA images is significantly less than on any stage of FA but closer to MA counts in the early phase of the FA. This suggests that patent MA with active blood flow are best represented on OCTA.
This is a 2021 ARVO Annual Meeting abstract.