Breakthrough research has shown that ranibizumab (Lucentis, Genentech, Inc.) eye injections, often in combination with laser treatment, result in better vision than laser treatment alone for treating diabetic macular edema (DME).1

The National Institutes of Health (NIH) study, published online in Ophthalmology, showed that nearly 50% of patients who received this new treatment experienced substantial visual improvement after 1 year, compared with 28% who received the standard laser treatment.

"These results indicate a treatment breakthrough for saving the vision of people with diabetic macular edema," Neil M. Bressler, MD, chair of the Diabetic Retinopathy Clinical Research Network and Chief of the Retina Division at the Wilmer Eye Institute, Johns Hopkins University, in Maryland, said in a news release. "Eye injections of ranibizumab with prompt or deferred laser treatment should now be considered for patients with characteristics similar to those in this clinical trial."

The study involved 52 clinical sites within the Diabetic Retinopathy Clinical Research Network (DRCR.net) and included a total of 854 eyes of 691 people. Participants, who were on average in their early 60s, were diagnosed with type 1 or 2 diabetes and macular edema. Patients were randomly assigned to one of four study groups: sham injection plus prompt laser treatment (n=293); ranibizumab 0.5 mg plus prompt laser treatment (n=187); ranibizumab 0.5 mg plus deferred laser treatment (≥24 weeks; n=188), or triamcinolone 4 mg plus prompt laser treatment (n=186). In general, treatment was continued until vision or retinal thickness returned to normal. Injections of ranibizumab could be given as often as every 4 weeks, and triamcinolone injections or laser treatments could be administered as often as every 16 weeks.

At the 1-year follow-up, mean change in the visual acuity letter score from baseline was significantly greater for patients who had received ranibizumab with prompt (9 ±11, P<.001) or deferred laser (9 ±12, P<.001) treatment compared with the group treated with laser alone (3 ±13). Patients treated with prompt or deferred laser treatment could read at least two additional lines on an eye chart, or letters that were at least one-third smaller with the treated eye than before the study treatment. Fewer than 5% of eyes in these groups experienced a visual loss of two or more lines, with similar results for prompt or deferred treatment groups. In comparison, 30% of eyes that received laser treatment alone or triamcinolone plus laser, gained two or more lines on an eye chart, while 13% to 14% of eyes lost two or more lines.

Reduction in mean central subfield thickness in the triamcinolone plus prompt laser group was similar to both ranibizumab groups and greater than the sham plus prompt laser group. In the subset of pseudophakic eyes at baseline (n=273), visual acuity improvement in the triamcinolone plus prompt laser group appeared comparable with the ranibizumab groups. However, patients who received triamcinolone injections reportedly had greater complication rates. According to the NIH, about 30% of people in the triamcinolone group developed high eye pressure that required medications, and about 60% developed cataracts that required surgery.

No systemic events attributable to study treatment were apparent, the study said. Three eyes (0.8%) had injection-related endophthalmitis in the ranibizumab groups, whereas elevated intraocular pressure and cataract surgery were more frequent in the triamcinolone plusprompt laser group.

DRCR.net researchers will continue to monitor the study participants for at least 3 years to obtain additional information about the safety and effectiveness of these macular edema treatments.

"This is a seminal study of which ophthalmology should be very proud," George A. Williams, MD, a board member of the American Academy of Ophthalmology, and Ophthalmology Department Chair, Oakland University William Beaumont School of Medicine, said in a news release. "First and most importantly, it provides patients an improved therapy for diabetic macular edema. Second, the DRCR Network study is the first multicenter, randomized clinical trial to show how ranibizumab and the laser work together to improve treatment."

Although ranibizumab is a US Food and Drug Administration-approved drug for age-related macular degeneration (AMD), it is not yet specifically approved for use with DME.

The study was supported by the National Eye Institute NEI and the National Institute of Diabetes and Digestive and Kidney Diseases, part of the NIH. For more information about this clinical trial (NCT00444600), visit www.clinicaltrials.gov.

  1. Elman M, Aiello L, Beck R, et al. Randomized trial evaluating ranibizumab plus prompt or deferred laser or triamcinolone plus prompt laser for diabetic macular edema. Ophthalmology. 27 April 2010. [Epub ahead of print]