Abstract
Purpose :
Fluorescein angiography is traditionally used to determine disease activity in proliferative diabetic retinopathy (PDR), but angiography is invasive and area of leakage over time can be difficult to evaluate. Optical Coherence Tomography Angiography (OCTA) allows non-invasive morphological evaluation of retinal neovascularization (NV) and could present a new method to evaluate PDR-activity. The purpose of this study was to evaluate area of NV, as measured by OCTA, as a marker of disease activity before and after panretinal photocoagulation (PRP) in patients with treatment-naïve PDR.
Methods :
This was a prospective study of 10 patients with treatment-naïve PDR. En face OCTA scans (4.5 mm x 4.5 mm, DRI OCT Triton swept source OCT) of NV were performed at baseline (BL) and 3-6 months after PRP, and areas were measured by ImageJ (National Institutes of Health) using the ‘Polygon selections’ tool. Wilcoxon signed-rank test was used to compare area at BL and follow up. The association of area of NV between BL and follow-up (FU) was given by Spearman’s rank correlation coefficient. Progression/regression of NVs was determined by fluorescein angiography and indirect ophthalmoscopy.
Results :
Median age was 51 years (range 36-80 years), and 50.0% were male. Median area of NV at BL and FU did not differ (1169.5 µm2 vs. 1153.1 µm2, p=0.17), but they were strongly, positively correlated (rs 0.96, p<0.0001). Four and six patients regressed and progressed in PDR-activity at FU. For those groups, median area of NV at BL and FU were 784.4 and 798.2 µm2 (regression), and 1458.8 and 1607.0 µm2 (progression).
Conclusions :
In patients with treatment-naïve PDR, there was a strong correlation between OCTA-measured area of retinal NV before and after PRP. Treatment response differed between smaller and larger NV with a better outcome for the former. This indicates that OCTA may serve as clinically useful tool to measure disease activity and adequacy of treatment response in PDR.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.