Abstract
Purpose :
Recent studies have shown visual field (VF) loss to be greater in eyes treated with pan-retinal photocoagulation (PRP) than in those treated with anti-VEGF for proliferative diabetic retinopathy (PDR); reasons for VF loss in eyes treated with anti-VEGF are yet unknown. To better understand VF loss that occurs after various PDR treatments, studying VF changes in untreated eyes may be helpful. However, after establishment of PRP as standard of care, eyes with PDR are rarely left untreated. This study used data from the Diabetic Retinopathy Study (DRS) to investigate the natural history of VF changes in untreated eyes with nonproliferative diabetic retinopathy (NPDR) or PDR.
Methods :
The DRS (1971-1979) was a randomized clinical trial evaluating the efficacy of PRP in persons with PDR in ≥ 1 eye or severe NPDR in both eyes. Participants had one eye randomized to PRP; the fellow eye was assigned to deferred treatment. VF data (Goldmann perimetry, IV4e test stimulus) were collected at baseline, 4 months, and then annually until 6 yrs. VF score was the sum of 12 meridian scores (for each meridian, peripheral extent of the field in degrees minus width of any scotomas). VF scores were analyzed over time among untreated eyes and for the paired difference between (argon)PRP-treated and fellow untreated eyes. Eyes that developed PDR with high-risk characteristics (HRC) in the deferral arm were treated with PRP and subsequently censored in the analyses.
Results :
1660 eyes (18% NPDR, 40% PDR/HRC) of 830 persons (44% female, age 43±14y) were included. Baseline VF score was 729±80. Among untreated eyes, VF score declined 30 /yr (95% CI, -35, -26) after adjustment for age, sex, and baseline PDR status and VF score. Difference in VF score between treated and untreated eyes was negative at 4 months, 1 yr, and 2 yrs (-32, -22, -20, p<.001 for all) (i.e., PRP-treated eyes had significantly lower VF scores than untreated eyes). After yr 3, differences were not statistically significant (yrs 3 through 6: 0.5, 11.4, 32.9, 18.4; p-values .96, .31, .05, .68).
Conclusions :
VF scores declined significantly in untreated eyes in the DRS, suggesting VF loss progresses over the natural history of PDR. VF loss was initially greater after PRP than in untreated eyes, but this difference diminished after yr 3.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.