Ranibizumab plus laser treatment may offer new option for treating diabetic macular edema, new research shows

The combination of ranibizumab injections and prompt or deferred laser treatment may be more effective in treating diabetic macular edema at least through 1 year relative to laser treatment alone, according to new Phase III data. The trial included 691 patients (mean age, 63 years) with type 1 or type 2 diabetes and diabetic macular edema involving the central macula. Most of the patients had 1 eye treated, but 24% had both eyes treated. Researchers randomized 854 eyes to 1 of 4...

The combination of ranibizumab injections and prompt or deferred laser treatment may be more effective in treating diabetic macular edema at least through 1 year relative to laser treatment alone, according to new Phase III data.

The trial included 691 patients (mean age, 63 years) with type 1 or type 2 diabetes and diabetic macular edema involving the central macula.

Most of the patients had 1 eye treated, but 24% had both eyes treated. Researchers randomized 854 eyes to 1 of 4 study groups: sham injections plus prompt focal/grid laser treatment within 1 week (n=293), ranibizumab injections plus prompt laser treatment (n=187), ranibizumab injections plus laser treatment deferred for at least 6 months (n=188), or triamcinolone acetonide injections plus prompt laser treatment (n=186).

The study team planned follow-up for 3 years, assessing the primary outcome of change in visual acuity from baseline at 1 year. Data were reported through Feb. 8, 2010, and included >=1 year of follow-up for 799 eyes and 2 years of follow-up for 484 eyes.

At 1 year, the visual acuity letter score increased from baseline by an average of 9 points for both of the ranibizumab groups; these improvements were significantly greater than the mean increase recorded in the sham injection plus laser group (3 points). The triamcinolone plus prompt laser group experienced a mean increase of 4 points in the visual acuity letter score.

Approximately 20% of both ranibizumab groups had a 10 to 14 letter improvement from baseline, which is equivalent to 2 lines on the eye chart, compared with 12% of the triamcinolone plus prompt laser group and 13% of the sham injection plus laser group. Thirty percent of the ranibizumab plus prompt laser group and 28% of the ranibizumab plus deferred laser group had an improvement of >=15 letters, which is equivalent to 3 lines on the eye chart.

The researchers noted that the 2-year outcomes generally mirrored the 1-year primary outcome results.

The study also showed that the ranibizumab groups were superior to the sham plus laser group in terms of retinal thickening at 1 and 2 years. Relative to the laser treatment alone, treatment with triamcinolone plus prompt laser resulted in a greater reduction in retinal thickening at 1 year but not at 2 years.

When the researchers analyzed a subgroup of pseudophakic eyes (n=273), triamcinolone plus prompt laser treatment performed similarly to both ranibizumab groups at improving visual acuity and reducing retinal thickening.

Neither ranibizumab nor triamcinolone were linked with a higher risk of systemic side effects or overall mortality. There was 1 case of progressive traction retinal detachment and 3 cases of injection-related endophthalmitis in the ranibizumab groups, while the triamcinolone group experienced elevated intraocular pressure and cataract surgery more frequently.

The researchers noted that other studies on ranibizumab for diabetic macular edema are under way and these results may further support the role of anti-vascular endothelial growth factor drugs alone or in combination with laser therapy in diabetic macular edema. Still, they stressed that further follow-up on the long-term safety and efficacy of ranibizumab, as well as its cost effectiveness, is necessary.

The investigators added that since 1985, focal/grid photocoagulation laser treatment has been the standard of care for diabetic macular edema. However, the current results revealed that ranibizumab plus laser treatment should be considered for this patient population.

The analysis was published ahead of print April 28 by the journal Ophthalmology by Elman MJ, et al.

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