Visual Field Changes in Diabetic Retinopathy: Natural History and after Pan-Retinal Photocoagulation in the Diabetic Retinopathy Study and the ETDRS.

Abstract

Objective: To examine visual field (VF) changes in untreated diabetic retinopathy (DR) and compare them to those in DR treated with pan-retinal photocoagulation (PRP).

Design: Post hoc analyses of the DR Study (DRS) and ETDRS, historical multicenter randomized controlled trials designed to assess the treatment effects of argon laser PRP for DR.

Participants: A total of 1660 DRS eyes (830 participants) with severe nonproliferative DR (NPDR) or proliferative DR (PDR), and 5416 ETDRS eyes (2708 participants) with mild-severe NPDR or early PDR.

Methods: Each DRS and ETDRS participant had 1 eye randomized to immediate PRP and the fellow eye to deferred PRP. Visual field scores (VFSs) were obtained with the Goldmann perimeter using the IV/4e stimulus in the DRS and the I/4e stimulus in the ETDRS. Eyes in the deferred PRP arm that later received PRP were censored at treatment initiation.

Main outcome measures: The outcomes of mean VFS and change from baseline VFS over time were estimated with multivariable regression models with repeated measures.

Results: Among untreated eyes (n = 830 [DRS] and n = 2,706 [ETDRS]), VFS change from baseline was -152.0 (95% confidence interval [CI], -215.4 to -88.5) at 6 years (DRS) and -79.2 (-90.9 to -67.6) at 7 years (ETDRS). Compared with untreated eyes with NPDR, untreated eyes with PDR + high-risk characteristics had VFS change of -50.2 (-65.9 to -34.6) and -38.8 (-69.2 to -8.5) in the DRS and ETDRS, respectively. Among untreated eyes, the presence of macular edema (ME) was associated with a VFS change of -12.9 (-25.4 to -0.5) and -6.2 (-10.4 to -1.9) in the DRS and ETDRS, respectively. The difference in VFS between PRP-treated versus untreated eyes was significant at 4 months (-31.4 [95% CI, -38.6 to -24.2]), but no longer apparent by year 3 (-1.4 [-17.0 to 14.1]) in the paired DRS analyses.

Conclusions: The natural history of untreated DR involved significant VF decline over time. Increased DR severity and presence of ME were associated with greater field loss. Pan-retinal photocoagulation was associated with a rapid initial decline in the VF; however, VFs in PRP-treated versus untreated eyes became similar by year 3.

Financial disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.