• Retina/Vitreous

    Review of: Panretinal photocoagulation for diabetic retinopathy in the RIDE and RISE trials: Not “1 and done”

    Gonzalez V, Wang P-H, Ruiz C. Ophthalmology, October 2021

    Investigators conducted a post hoc analysis evaluating panretinal photocoagulation (PRP) treatment and re-treatment patterns in the Phase 3 randomized, controlled RIDE and RISE clinical trials of ranibizumab.

    Study design

    This trial included 759 patients with diabetic retinopathy (DR), approximately 25% of whom had received PRP prior to enrollment. Patients were randomized 1:1:1 to receive monthly intravitreal sham injections or monthly injections of ranibizumab 0.3 mg or 0.5 mg. Clinical experiences and PRP treatment patterns were assessed by baseline PRP treatment status. The study evaluated the need for repeat PRP over 24 months in those patients who were treated prior to entry, and the efficacy of initial PRP in untreated patients in both the sham injection and ranibizumab arms.

    Outcomes

    In patients without PRP prior to study entry, 10% of sham-treated eyes and 1%–2% of ranibizumab-treated eyes required ≥1 PRP treatments by month 24. In patients who received prior PRP, 19% of those given sham injection required ≥1 PRP treatments through month 24, whereas none of those given ranibizumab required additional PRP during the study. Treatment with ranibizumab was found to reduce DR progression in patients who had been given PRP. Patients in the sham treatment group had more clinical events than patients in the ranibizumab groups, regardless of prior PRP status.

    Limitations

    The analysis of PRP frequency in each group was not a prespecified endpoint of the study; thus, findings of this post hoc analysis should be interpreted with caution.

    Clinical significance

    Multiple prior studies have noted regression of DR after treatment with anti-VEGF agents. Many patients did not qualify for these studies due to the need for dialysis, extremely high glycated hemoglobin levels, uncontrolled hypertension, and other risk factors; therefore, patients with the most severe disease were not being enrolled. Since the introduction of PRP as the standard of care for the treatment of proliferative DR, retina specialists have understood that a complete PRP often cannot be delivered in one session. Frequent follow-up is recommended for all patients with diabetes, but a prior full laser treatment can be what prevents a nonadherent patient from progressing to a tractional retinal detachment and irreversible vision loss. Combination therapy with PRP and anti-VEGF agents is often the most beneficial in this patient population.