Abstract
Purpose :
To evaluate intrasession and between-visit reproductibility of macular non-flow area and macular vessel-density values in patients with diabetes.
Methods :
A total of 44 eyes of 22 diabetic patients underwent OCT angiography imaging (RTVue-XR Avanti; Optovue, Fremont, CA, USA). Central non-flow area and vessel density (VD) was examined in the central area with a radius of 3.0 mm from the foveolar center using the AngioAnalytics software. Three images were acquired in one visit and one image 1 month later. Intrasession and between-visit coefficient of variation (CV) values were determined for the central non-flow area, and for vessel density in the 3.0 mm macular area and in the perifoveal ring.
Results :
There was no significant difference in the mean non-flow area between the two visits (0.30±0.11 mm2 vs. 0.31±0.11 mm2; p>0.05). Similarly, there was no significant difference in 3.0 mm vessel density (47.94±3.85% vs. 47.70±3.96%; p>0.05) and in perifoveal vessel density (49.48±4.08 vs. 49.26±4.19%; p>0.05) between the two visits. The intrasession CV was higher in the non-flow area compared to CV values of vessel density in the 3.0 mm macular area and in the perifoveal ring (7.05% vs. 3.37% and 3.60%; p<0.05). Similarly, the between-visit CV was higher in the non-flow area compared to CV values of the 3.0 mm macular area and the perifoveal ring (9.63% vs. 3.82% and 3.81%; p<0.05). There was no statistically significant difference between intrasession and between-visit CV values of the analyzed parameters (p>0.05). Between-visit variability of data was negatively correlated with macular vessel density (3 mm area: r=-0.35; p<0.05, perifoveal ring r=-0.38; p<0.05).
Conclusions :
Repeated OCT angiography measurement of macular vessel density revealed excellent repeatability, indicating that this non-invasive technology is sufficient for longitudinal assessment of microvascular complications in diabetes. Measurement of the macular non-flow area had higher variance, suggesting that this parameter is less reliable in the analysis of the vascular aspects of diabetic retinopathy and monitoring of disease progression and the effect of treatments.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.