Assessment of the DRCR Retina Network Approach to Management With Initial Observation for Eyes With Center-Involved Diabetic Macular Edema and Good Visual Acuity: A Secondary Analysis of a Randomized Clinical Trial

IMPORTANCE: Among eyes with center-involved diabetic macular edema (CI-DME) and good visual acuity (VA), randomized clinical trial results showed no difference in VA loss between initial observation plus aflibercept only if VA decreased, initial focal/grid laser plus aflibercept only if VA decreased, or prompt aflibercept. Understanding the initial observation approach is relevant to patient management. OBJECTIVE: To assess the DRCR Retina Network protocol-defined approach and outcomes of initial observation with aflibercept only if VA worsened. DESIGN, SETTING, AND PARTICIPANTS: This was a post hoc secondary analyses of a randomized clinical trial of the DRCR Retina Network Protocol V that included 91 US and Canadian sites from November 2013 to September 2018. Participants were adults (n = 236) with type 1 or 2 diabetes, 1 study eye with CI-DME, and VA letter score at least 79 (Snellen equivalent, 20/25 or better) assigned to initial observation. Data were analyzed from March 2019 to November 2019. INTERVENTIONS: Initial observation and follow-up with aflibercept only for VA loss of at least 10 letters from baseline at 1 visit or 5 to 9 letters at 2 consecutive visits. Follow-up occurred at 8 weeks and then every 16 weeks unless VA or optical coherence tomography central subfield thickness worsened. MAIN OUTCOMES AND MEASURES: Whether individuals received aflibercept. RESULTS: Among 236 eyes in 236 individuals (149 [63%] male; median age, 60 years [interquartile range, 53-67 years]) randomly assigned to initial observation, 80 (34%) were treated with aflibercept during 2 years of follow-up. At 2 years, the median VA letter score was 86.0 (interquartile range, 89.0-81.0; median Snellen equivalent, 20/20 [20/16-20/25]). Receipt of aflibercept was more likely in eyes with baseline central subfield thickness at least 300 μm (Zeiss-Stratus equivalent) vs less than 300 μm (45% vs 26%; hazard ratio [HR], 1.98 [95% CI, 1.26-3.13], continuous P = .005), moderately severe nonproliferative diabetic retinopathy (Early Treatment Diabetic Retinopathy Study retinopathy severity level 47) and above vs moderate nonproliferative diabetic retinopathy (retinopathy severity level 43) and below (51% vs 27%; HR, 2.22 [95% CI, 1.42-3.47], ordinal P