Refractive Error Change During Diabetic Macular Edema Treatment: A Post Hoc Analysis of the DRCR Protocol T Trial

Abstract

Purpose : To evaluate the impact of anti-VEGF therapy and changes in optical coherence tomography (OCT) metrics on the refractive error (RE) in diabetic macular edema (DME).

Methods : A post-hoc analysis of DRCR protocol T. The RE in diopters (D) was measured using standard protocol refraction. Spherical equivalent (SE) data was calculated for study and fellow eyes at baseline, one-year, and two-year visits. The SE change of the eyes with persistent edema was compared to those with resolved edema stratified by lens status. The correlation between RE changes and OCT metrics like baseline fluid and central subfield thickness (CST) was evaluated.

Results : Among 543 patients, a small hyperopic shift was found from baseline to the 1-year follow up in the study eye [0.06 (0.67), p= p=0.015] and the fellow eye [ 0.07 (0.75), p=0.013]. A small hyperopic shift was also observed from baseline to the 2-year follow-up in the study eye [ 0.04 (0.82), p=0.022] and the fellow eye [ 0.12 (0.84), p= 0.001]. There was no significant difference between the SE change of the study and fellow eyes at 1-year and 2-year visits (p= 0.89 and 0.23, respectively). No significant difference in SE shift was found between eyes with and without edema at two years in phakic (0.12 D and 0.08, p=0.87) and pseudophakic eyes (-0.24 and -0.08, p=0.30). In phakic patients, SE change was significantly different in eyes with no edema at 1-year and 2-year visits and baseline (IRF+/SRF-) vs. eyes with baseline (IRF+/SRF+), both at one year [0.19 (0.63) vs. -0.03 (0.85), respectively, p=0.003] and two years follow up [0.16 (0.74) vs. -0.14 (0.98), respectively, p= 0.039]. In pseudophakic patients, no significant difference was noted between SE change of eyes with no edema at 1-year and 2-year visits and baseline (IRF+/SRF-) compared to eyes with baseline (IRF+/SRF+) at one year [-0.01 (0.53) vs. 0.03 (0.55), respectively, p=0.93] and two years [-0.09 (0.63) vs. -0.08 (0.51) , respectively, p=0.77]. The SE shift was not correlated with CST change at the end of the first (r=0.013, p=0.77) nor the second year (r=0.02, p=0.62).

Conclusions : DME patients receiving anti-VEGF therapy have minimal changes in RE. Appropriate refraction may be considered at any point regardless of edema.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

Table 1. The spherical equivalent and its change in the study and fellow eye.

 

Table 2. Spherical equivalent changes in eyes with or without edema.