Abstract
Purpose :
To determine the intersession repeatability over two visits 12 weeks apart and annual change in OCTA metrics, best corrected visual acuity (BCVA) and low-luminance visual acuity (LLVA) in two cohorts with diabetic macular ischaemia
Methods :
This prospective study was conducted in two centres. Patients with stable treated proliferative diabetic retinopathy (PDR) with OCTA evidence of diabetic macular ischaemia defined on OCTA as foveal avascular zone (FAZ) ≥0.5 mm2 or parafoveal capillary dropout ≥1 quadrant were recruited and followed up at 12,24 and 52 weeks. At each visit, BCVA, LLVA and OCTA 3x3mm (Avanti RTVUE-XR; Optovue, CA, USA) were repeated. The coefficient of repeatability of OCTA metrics, BCVA and LLVA were evaluated between baseline and 3 months. The annual change in these metrics was evaluated using linear mixed-effects models with unstructured variance accounting for within-participant correlation between the study eye and repeated measures across time. Fixed effects adjusted for include the main effects and their interaction with time (based on data available at each visit) in age and diabetes duration
Results :
A total of 161 eyes of 122 patients were included. The mean age was 57.8 (SD 11.4), 45 (36.9%) were women and the median duration of diabetes was 22.0 years (IQR 15.0-31.5). The inter-session coefficient of repeatability between baseline and 3 months is shown in Figure 1. Table 2 shows the mean change of BCVA, LLVA and OCTA metrics at 3 months and 12 months. The mean annual increase in FAZ area and FAZ circularity were 0.027 mm2 and 0.138 mm respectively. The mean annual change of total superficial vascular density (SVD) and total deep vascular density (DVD), parafoveal SVD and DVD were +0.036, +0.301, +0.228 and +0.029%. The annual change of parafoveal 300-um ring vessel density (FD-300) was 0.168%.
Conclusions :
The Intersession coefficient of repeatability of OCTA vascular metrics is high and BCVA has a coefficient of repeatability of about 10 letters. The annual changes in OCTA vascular metrics are <1% and visual function changes are minimal, confirming a slowly progressive disease.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.