Abstract
Purpose :
To evaluate PRP vs IVR effects on choroidal thickness, and retinal thickness and integrity in eyes with proliferative diabetic retinopathy (PDR) requiring treatment.
Methods :
This is a post hoc analysis of Protocol S participants randomized to PRP or IVR to treat PDR. The data source is the DRCR Retina Network, but the content and conclusions presented herein are solely the responsibility of the authors and have not been reviewed or approved by the network. Zeiss Cirrus map and Heidelberg Spectralis raster line OCT images at baseline, 2 and 5 years were evaluated. Choroidal thickness (between Bruch’s membrane and the choroid-sclera junction) was manually measured at a single point using calipers in the devices’ software at the fovea, and the superior and inferior outer ring center points. The images were evaluated for foveal central subfield (FCS) thickness, total retinal volume (TRV), disorganization of retinal inner layers (DRIL), external limiting membrane (ELM) integrity and ellipsoid zone (EZ) integrity.
Results :
Choroidal thickness was graded in 159 of 177 PRP and 143 of 166 IVR eyes at baseline, 135 PRP and 119 IVR at 2 years, and 67 PRP and 62 IVR at 5 years. Mean change from baseline choroidal thickness at the fovea (-3 vs -6 and -8 vs -11 um), superiorly (-4 vs -6 and -15 vs -11 um), and inferiorly (-13 vs -14 and -27 vs -19 um) for PRP vs IVR at 2 and 5 years were not significantly different between treatments (all p>.05). The decreases compared to baseline were significant in both groups superiorly at 5 years (both p=.03), and inferiorly at 2 and 5 years (both p = .003 at 2 years; p<.001 for PRP and p=.003 for IVR at 5 years). Mean change from baseline FCS (8 vs -39 and -4 vs -39 µm) and TRV (-.03 vs -.79 and -.39 vs -1.07 mm3) for PRP vs IVR at 2 and 5 years were significantly different between treatments (p<.001 and p=.04 for FCS; p<.001 and p=.01 for TRV). Rates of DRIL (52% vs 39% and 58% vs 56%), ELM (58% vs 64% and 52% vs 46%), and EZ (53% vs 58% and 52% vs 49%) for PRP vs IVR at 2 and 5 years were similar.
Conclusions :
In this randomized cohort, we did not find differences in choroidal thickness changes between PRP and IVR from baseline to 2 or 5 years. Both study arms had significant decreases in superior and inferior choroidal thickness at 5 years. IVR had greater FCS thickness and TRV reductions than PRP.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.