Focal/grid laser treatment does not reduce ranibizumab injection frequency for macular edema
Data from the ZIPANGU study showed the use of focal/grid short-pulse laser therapy in patients receiving ranibizumab injections for the treatment of macular edema secondary to branch retinal vein occlusion did not reduce the number of necessary injections compared with patients undergoing ranibizumab monotherapy, according to a presenter at the virtual Association for Research in Vision and Ophthalmology meeting.
However, the study data suggested patients could experience similar visual acuity improvements with fewer injections when compared with data in previous clinical trials, Toshinori Murata, MD, PhD, said.
“The initial ranibizumab injection was performed within 2 months from the onset of vision deterioration in most of the patients. This early intervention appears to be the key treatment, which may be sufficient with the median four anti-VEGF injections per year in treatment-naive cases,” he said.
The phase 4 study included 59 patients with macular edema secondary to BRVO. Murata said 30 patients were treated with a combination of as-needed 0.5 mg ranibizumab and laser therapy and 29 patients were treated with as-needed 0.5 mg ranibizumab monotherapy. The primary endpoint of the study was the difference in the mean number of injections, with a secondary endpoint of the mean change in visual acuity between the two cohorts.
Additional injections were given if patients experienced central subfield thickness of 300 µm or greater, a 20% increase from the lowest value in central subfield thickness during the treatment period or a decrease in visual acuity due to disease activity.
Additional grid laser treatment was performed if an OCT map showed clinically significant macular edema thicker than 350 µm, if the presence of capillary nonperfusion to suppress VEGF overprotection was observed or if treatable lesions were found. Focal short-pulse laser was performed if leakage points were located 500 µm or more outside of the fovea, Murata said.
The mean number of ranibizumab injections between the two groups was not statistically different at 12 months, with the combination cohort undergoing 4.1 injections compared with 4.3 in the monotherapy cohort. By month 12, monotherapy patients had gained an average of 22 letters from baseline compared with 15 letters in the combination cohort, a statistically significant difference (P = .035).
The number of necessary injections did not significantly differ between the two cohorts, but Murata said the data show the possibility of patients experiencing similar gains in visual acuity with just four ranibizumab injections a year when compared with past trials of ranibizumab to treat macular edema secondary to BRVO, such as the BRIGHTER and BRAVO studies. – by Robert Linnehan
Murata T. Comparison of ranibizumab with or without focal/grid laser for macular edema secondary to branch retinal vein occlusion: 12-month results from the ZIPANGU study. Presented at: Association for Research in Vision and Ophthalmology annual meeting; May 6, 2020 (virtual meeting).
Disclosure: Murata reports he receives financial support from Novartis Pharma, Bayer and Carl Zeiss Meditec.