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From SCORE and CRUISE to COPERNICUS and GALILEO, numerous studies have shed light on the safety and efficacy of therapies for macular edema (ME) related to central retinal vein occlusion (CRVO). Recently, the Academy’s Ophthalmic Technology Assessment (OTA) committee reviewed the literature on treatment of ME linked with CRVO and encapsulated high-level evidence for clinicians.1
Role of the OTA. The OTA committee consists of vitreoretinal physicians and a methodologist, who evaluate new and existing therapies and diagnostic tests for retinal disorders, said Steven Yeh, MD, lead author and associate professor of ophthalmology at Emory University in Atlanta.
“One of the main goals is to evaluate the quality of the evidence and to formulate an assessment of various therapies’ clinical effectiveness and safety,” he said. “This is vetted not only by the OTA committee, but also by the American Academy of Ophthalmology and major retinal organizations, including the Macula Society, Retina Society, and American Society of Retina Specialists.”
Robust evidence for anti-VEGF. Targeting a condition that affects at least 2.5 million people worldwide, the OTA committee searched PubMed and the Cochrane Library and identified 108 citations on CRVO, of which 20 were clinically relevant for review.1 “We found a high level of level 1 evidence [seven citations representing four clinical trials] supporting the use of anti–vascular endothelial growth factor therapy for ME associated with CRVO,” said Dr. Yeh. “All three major anti-VEGF agents—intravitreal [IVT] ranibizumab, aflibercept, and bevacizumab—demonstrated improvements in visual acuity and reduction of macular edema as seen with OCT scanning.”
In these trials, early treatment was vital for achieving a three-line visual gain, added Dr. Yeh. “The likelihood of visual gain decreased by almost 50 percent in all three treatment groups if treatment was withheld during the first six months.”
Other therapies. In addition, there was level 1 evidence supporting the efficacy of IVT corticosteroid therapy, either triamcinolone injection (two citations) or dexamethasone implant (one citation). When compared with anti-VEGF therapies, however, steroids were associated with a higher frequency of cataract and glaucoma.
Level 1 evidence from one citation also revealed limited benefits from macular grid laser photocoagulation. Other citations reviewed by the committee demonstrated levels 2 and 3 evidence on that therapy.
Remaining questions. Variations in study designs and protocols sometimes made “apples-to-apples” comparisons difficult, noted Dr. Yeh. For example, patients were excluded from the CRUISE study if they had a relative afferent pupillary defect and ME for more than 12 months, but they were allowed in SCORE.
“Without the benefit of very strict comparative efficacy studies, you can over-interpret or underinterpret differences in efficacy outcomes of treatment groups,” he said.
Although this OTA review provides strong guidance for clinicians, said Dr. Yeh, additional research is needed in areas such as combination therapies, treatment algorithms, and novel delivery methods.
“There may not be a cookbook recipe for CRVO,” he said, “especially given that macular ischemia and inflammation play a stronger role in some of these patients than in others.”
—Annie Stuart
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1 Yeh S et al. Ophthalmology. 2015;122(4):769-778.
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Dr. Yeh is a consultant for Clear-side Biomedical.
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