Influence of Ranibizumab versus laser photocoagulation on radiation retinopathy (RadiRet) - a prospective randomized controlled trial

Purpose: To demonstrate superiority of intravitreal ranibizumab 0.5 mg compared to focal and peripheral laser treatment in patients with radiation retinopathy for choroidal melanoma. Methods: Inclusion criteria were as follows: patients with radiation retinopathy and visual acuity impairment due to radiation maculopathy accessible for laser therapy, age ≥ 18 years, and BCVA less than 20/32. The main objective was to study the change in best-corrected visual acuity (BCVA) over 6 months from ranibizumab 0.5 mg (experimental) compared to focal laser of the macula and panretinal laser treatment of the ischemic retina (control) in patients with radiation retinopathy in choroidal melanoma. The secondary objectives of the radiation retinopathy study were to compare functional and anatomical results between ranibizumab and laser group over 12 months and to measure the frequency of vitreous hemorrhage and rubeosis iridis. Results: The intention-to-treat analysis included 31 patients assigned to ranibizumab (n = 15) or laser treatment (n = 16). In terms of BCVA at month 6, ranibizumab was superior to laser treatment, with an advantage of 0.14 logMAR, 95% CI 0.01 to 0.25, p = 0.030. The positive effect of ranibizumab disappeared after treatment was discontinued. Similar results without statistically significant difference were found with respect to macular thickness. In both groups, no change was observed at month 6 in the size of ischemia in the macula or periphery compared to baseline. There was 1 case of vitreous hemorrhage in the laser group and no case of rubeosis iridis over time. Conclusions: This study showed a statistically significant improvement in visual acuity and clear superiority of ranibizumab compared to laser treatment up to 26 weeks, but this effect disappeared at week 52 after completion of intravitreal treatment. Ranibizumab and PRP are considered equivalent in terms of the non-appearance of proliferative radiation retinopathy during the study. Trial registration: EudraCT Number: 2011-004463-6