Abstract
Purpose :
To assess the value of electroretinography (ERG), OCT-angiography (OCT-A), and ultra-wide field fluorescein angiography (UWF-FA) parameters to predict progression of diabetic retinopathy in eyes with moderate to severe non-proliferative diabetic retinopathy (NPDR).
Methods :
In the TIME-2b trial 167 patients with NPDR were randomized to receive 48 weeks of treatment with AKB-9778 (a Tie2 activator) 15 mg once or twice daily, or placebo. Eligible eyes had ETDRS DR severity (DRSS) of 43, 47 or 53, BCVA of 20/30 or better, and no center-involved DME. Measurements at baseline included non-mydriatic flicker ERGs (71 patients; RETeval device, DR Assessment protocol, Maa et al. 2016), OCT-A (74 patients), and OPTOS UWF-FA (101 patients). DRSS was graded on 7-field fundus photographs. Progression to DME was defined as an increase of central subfield thickness of ≥ 20% or an adverse event of DME confirmed by the image reading center. PDR was defined as a DRSS of >53, an AE involving neovascularization, or treatment for PDR. ROC analysis was used to assess predictive value of baseline measurements and pairs thereof.
Results :
AKB-9778 did not have a statistically significant effect on DRSS or progression to DME/PDR, so data from all study arms were combined. 42 eyes progressed to DME/PDR; 21 of these eyes had ERGs, 17 had OCT-A, and 13 had UWF-FA. UWF-FA ischemia index, leakage index, and micro-aneurysm count were not predictive of progression. Statistically significant predictors (from worst to best, AUROC, 95% CI) include increased DRSS level (.60, .51–.69), decreased pupil response during ERG testing (.67, .55–.77), increased OCT-A FAZ area (.68, .52–.82), increased OCT-A total vessel length (.68, .56–.80), increased flicker implicit time (.73, .61–.83), and increased DR Assessment score (.79, .70–.87). The best pair was a logistic regression of the ERG-based DR Assessment score and OCT-A non-perfusion area (.86, .75–.94). When both tests were abnormal 73% (8/11) of eyes progressed. When both tests were normal 3.6% (1/28) of eyes progressed.
Conclusions :
Prediction of progression of NPDR is important in the management of the disease. Pre-treatment ERG and OCT-A parameters were better predictors of progression to DME/PDR than DRSS or UWF-FA over 48-weeks of follow-up. The combination of functional and structural measures was better than either alone.
This is a 2020 ARVO Annual Meeting abstract.