Panretinal Photocoagulation vs Intravitreous Ranibizumab for Proliferative Diabetic Retinopathy: A Randomized Clinical Trial

Abstract

IMPORTANCE

Panretinal photocoagulation (PRP) is standard treatment for reducing severe visual loss from proliferative diabetic retinopathy (PDR). However, PRP can damage the retina, resulting in peripheral vision loss or worsening diabetic macular edema (DME).

OBJECTIVE

Compare ranibizumab versus PRP for PDR.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial (55 U.S. sites) assessing non-inferiority of ranibizumab compared with PRP for vision outcomes; 305 adults with PDR enrolled February-December 2012 (mean age 52, 44% female, 52% white). Both eyes enrolled for 89 participants totaling 394 study eyes. The final 2-year visit was completed January 2015.

INTERVENTIONS

Ranibizumab group (N=191 eyes): intravitreous 0.5-mg ranibizumab and, PRP if treatment failed; ranibizumab as needed for DME. PRP group (N=203 eyes): PRP; ranibizumab as needed for DME.

MAIN OUTCOMES AND MEASURES

Primary: mean visual acuity change at 2 years (5-letter non-inferiority margin; intention-to-treat analysis). Secondary: visual acuity area under the curve, peripheral visual field loss, DME development, neovascularization, vitrectomy, and safety.

RESULTS

Mean visual acuity letter improvement at 2 years was +2.8 in the ranibizumab group versus +0.2 in the PRP group (difference +2.2, 95% confidence interval [CI]: −0.5 to +5.0, non-inferiority P<0.001). Mean treatment group difference in visual acuity area under the curve over 2 years was +4.2 (95% CI: +3.0 to +5.4, P<0.001). Visual field sensitivity loss was worse (mean dB difference 372; 95% CI: 213 to 531, P<0.001), vitrectomy more frequent (15% versus 4%, difference 9%, 95% CI: 4% to 15%, P<0.001), and DME development more frequent (28% versus 9%, difference 19%, 95% CI: 10% to 28%, P<0.001) in the PRP versus ranibizumab group, respectively. Eyes with neither active nor regressed neovascularization at 2 years was similar (35% [ranibizumab group] versus 30% [PRP group], difference 3%, 95% CI: −7% to 12%, P=0.58). One eye (ranibizumab group) developed endophthalmitis. No significant differences between groups in rates of major cardiovascular events were identified.

CONCLUSION

Among eyes with PDR, treatment with ranibizumab resulted in visual acuity that was non-inferior to (not worse than) PRP treatment at two years. Although longer term follow-up is needed, ranibizumab may be a reasonable treatment alternative, at least through 2 years, for patients with PDR.