The RELATION study: efficacy and safety of ranibizumab combined with laser photocoagulation treatment versus laser monotherapy in NPDR and PDR patients with diabetic macular oedema.

Purpose: To assess efficacy and safety of intravitreal ranibizumab 0.5 mg plus laser (COMBI) versus laser monotherapy (LASER) in patients with visual impairment due to diabetic macular oedema (DME) in either nonproliferative diabetic retinopathy (NPDR) or proliferative diabetic retinopathy (PDR) and to analyse the relevance of inner versus outer retinal thickness.

Methods: In this double-masked, multicentre phase IIIb study, patients (N = 128) were randomized (2:1) to receive COMBI (n = 85) versus LASER (n = 43). Patients received four initial monthly injections of ranibizumab 0.5 mg (COMBI) or sham (LASER) followed by pro re nata (PRN) injections. In both groups, patients received laser at baseline and additional laser at 3 monthly intervals, as needed. The study was started in 2010 and was prematurely terminated due to approval of ranibizumab for DME.

Results: The least squares (LS) mean change in mean best-corrected visual acuity (BCVA) from baseline to month 12 was higher in the COMBI (6.5) versus LASER (2.3) group (LS mean difference: 4.2 [95% CI 0.9; 7.4] letters, p = 0.01, primary end-point). There was also a tendency in the same direction for the subgroup of 26 patients with PDR (LS mean difference 14.7, p = 0.11). Mean central retinal thickness decreased by 107.3 μm in the COMBI group and by 80.3 μm in the LASER group from baseline to month 12 (p = 0.28). Ranibizumab was well tolerated.

Conclusion: This study showed that ranibizumab plus laser is a valuable treatment option for the management of DME. Patients with DME in PDR might also benefit from combined therapy compared to laser alone.