SAN DIEGO — Results are no better when focal or grid laser treatment coincides with the initiation of intravitreal ranibizumab for the treatment of diabetic macular edema than when laser treatment is deferred for 24 weeks or more, new research shows.
However, "deferral may require more injections over 5 years to achieve the results seen in this study," John Wells, MD, from the Palmetto Retina Center in Columbia and assistant professor at the University of South Carolina, said here at the 32nd Annual Meeting of the American Society of Retina Specialists (ASRS).
Previous reports have suggested that intravitreal ranibizumab in combination with either prompt or deferred laser treatment is more effective than laser treatment alone.
In addition, a 3-year comparison of ranibizumab groups showed that prompt laser use is no better than deferred laser use, and is possibly worse (Ophthalmology. 2012;119:2312-2318).
To understand the longer-term results, Dr. Wells and his team conducted a multicenter prospective randomized clinical trial of patients with diabetic macular edema and impaired vision, and followed them for 5 years.
All the eyes were treated with ranibizumab 0.5 mg every 4 weeks until the eye was no longer improving (or until the investigator decided to stop). Eyes were randomly assigned to either prompt or deferred laser treatment. The deferred group received laser treatment at least 24 weeks after the initiation of ranibizumab, and only if the diabetic macular edema was not improving.
After 5 years, patients in the deferred group gained 2.6 more letters of visual acuity than those in the prompt group, but the difference was not statistically significant (P = .09). However, significantly more patients in the deferred group than in the prompt group gained more than 15 letters (38% vs 27%; P = .03). In addition, 56 patients in the deferred group were able to forgo laser treatment altogether.
There was no difference in safety between the 2 groups, although patients in the deferred group needed a median of 4 injections more than those in the prompt group.
Table. Five-Year Outcomes in Patients Treated With Ranibizumab and Laser Therapy
|Outcome||Prompt Laser Treatment, n||Deferred Laser Treatment, n|
|Eyes completing the study||124||111|
|Eyes not completing the study||54||70|
|Increase in letters of visual acuity||7.2||9.8|
These results are consistent with those from previous research, which have shown that ranibizumab alone might be superior to laser treatment in this condition, said session moderator and ASRS president John Thompson, from the University of Maryland in Baltimore.
"Increasingly, it appears that focal laser does not have a role in the treatment of diabetic macular edema," Dr. Thompson said.
Dr. Wells reports financial relationships with Alcon, Allergan, DRCR Network, Genentech, Lpath, Novartis, Ophthotech, and Regeneron. Dr. Thompson has disclosed no relevant financial relationships.
32nd Annual Meeting of the American Society of Retina Specialists (ASRS). Presented August 11, 2014.
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Cite this: Prompt or Delayed Laser Equal in Diabetic Macular Edema - Medscape - Aug 14, 2014.