Course of Diabetic Retinopathy in Untreated Fellow Eyes in RIDE and RISE: A Post Hoc Analysis

BACKGROUND AND OBJECTIVE: To characterize diabetic retinopathy (DR) progression without therapy. PATIENTS AND METHODS: This post hoc analysis of the phase 3 RIDE and RISE trials examined the association between baseline DR severity on rates of >_ 2-step DR progression and improvement in untreated fellow eyes (n = 530) and ranibizumab-treated study eyes (n = 369). Kaplan-Meier analyses estimated progression to proliferative DR (PDR) over 2 years in eyes with nonproliferative DR (NPDR) at baseline. RESULTS: At month 24, 28.8% of untreated fellow eyes with moderately severe to severe NPDR at baseline experienced >_ 2-step DR progression, versus 10.3% of eyes with absent to moderate NPDR and 0 eyes with mild-to high-risk proliferative DR. Of the untreated fellow eyes with moderately severe to severe NPDR, 18.9% achieved >_ 2-step DR improvement, compared with 88.4% of ranibizumab-treated eyes. CONCLUSION: Without treatment, patients with moderately severe to severe NPDR are at risk of rapid disease progression and vision loss.