Panretinal Photocoagulation for Diabetic Retinopathy in the RIDE and RISE Trials: Not "1 and Done"

Abstract

Purpose: To evaluate panretinal photocoagulation (PRP) treatment and re-treatment patterns in patients with diabetic retinopathy (DR) and diabetic macular edema (DME).

Design: Post hoc analysis of the phase 3 RIDE (clinicaltrials.gov identifier, NCT00473382) and RISE (clinicaltrials.gov identifier, NCT00473330) clinical trials of ranibizumab for the treatment of DME.

Participants: Seven hundred fifty-nine patients were randomized for treatment.

Methods: Panretinal photocoagulation treatment patterns and clinical experiences were assessed by baseline PRP treatment status.

Main outcome measures: Number and timing of on-study PRP treatment sessions undergone through month 24. Time to new proliferative event (composite end point) was also assessed.

Results: At baseline, approximately 25% of patients in RIDE and RISE had undergone PRP treatment before enrollment (22.2%, 24.4%, and 25.4% of patients in the sham, ranibizumab 0.3 mg, and ranibizumab 0.5 mg arms, respectively). In patients without prior PRP at baseline (n = 577), 9.5% of sham-treated patients underwent 1 or more PRP treatments through month 24, compared with 1.1% and 1.6% of patients receiving ranibizumab 0.3 mg and ranibizumab 0.5 mg, respectively (P < 0.001 for both ranibizumab arms vs. sham). In patients with prior PRP at baseline (n = 182), 19.3% of sham-treated patients underwent 1 or more PRP treatments through month 24. No ranibizumab-treated patients with prior PRP at baseline required additional on-study PRP through month 24 (P < 0.001 for both ranibizumab arms vs. sham). Ranibizumab treatment also significantly reduced clinical DR progression among patients who underwent prior PRP. By month 24 in patients with prior PRP at baseline, the probability of experiencing a new proliferative event was 10.3% and 9.9% in patients receiving ranibizumab 0.3 mg and ranibizumab 0.5 mg treatment, respectively, compared with 39.4% in sham-treated patients (P < 0.0001). Overall, sham-treated patients, including those patients who were PRP naïve at baseline who went on to require PRP, experienced more clinical events than ranibizumab-treated patients.

Conclusions: In RIDE and RISE, PRP treatment was not a "1 and done" procedure, with on-study PRP re-treatment occurring in patients both with and without prior PRP treatment at baseline. Ranibizumab treatment reduced on-study PRP treatment and DR progression regardless of prior PRP treatment status at baseline.