A treatment for retinal vein occlusion yields long-lasting vision gains, with visual acuity remaining significantly above baseline at five years – though many patients still require ongoing treatment, according to a report published in the American Journal of Ophthalmology. The report marked the five-year outcomes of the Study of Comparative Treatments for Retinal Vein Occlusion 2 (SCORE2).
Retinal vein occlusion (RVO) is caused by a blockage of the veins carrying blood away from the retina, causing macular oedema where fluid becomes trapped within and under the retina, leading to rapid and severe loss of visual acuity. Central retinal vein occlusion (CRVO) is an occlusion of the main retinal vein posterior to the lamina cribrosa of the optic nerve. CRVO has a better prognosis in younger patients. One-third of older patients improve without treatment, one-third stay the same, and one-third get worse.
The leading treatment for RVO is injections of anti-vascular endothelial growth factor (VEGF) drugs, helping to control blood vessel leakage and swelling.
“While anti-VEGF therapy is associated with significant improvement in both retinal swelling and visual acuity in patients with central or hemi-retinal vein occlusion, our findings show that most of the patients followed still required treatment to control the macular oedema for at least five years,” said the chair of the study, Ingrid U. Scott, MD, MPH, at the Penn State College of Medicine. “This demonstrates the importance of continued monitoring of these patients.”
In 2017, SCORE2 clinical trial investigators reported that two types of anti-VEGF treatment were equally effective at improving visual acuity in people with macular oedema due to CRVO or hemi-retinal vein occlusion (HRVO). CRVO affects the entire retina, while HRVO generally affects about half of the retina. Half of the study participants had received bevacizumab while the other half received aflibercept. Participants received monthly injections over six months. At the six-month mark, the vision of participants in both groups had, on average, improved over three lines on an eye chart.
The researchers followed SCORE2 participants for five years, collecting information about their visual acuity, treatments, and whether their macular oedema had resolved. After the initial 12-month study period, participants were treated at their physician’s discretion, most reducing the frequency of anti-VEGF injections and some switching their patients to the other anti-VEGF drug. At five years, many participants had lost some visual acuity compared to the 12-month mark, but they retained on average three lines of improvement compared to baseline.
“It was surprising to us that despite many participants still needing treatment after five years, their visual acuity outcome remained very good,” said Dr Michael Ip, MD, co-chair of the study from the University of California Los Angeles. “In comparison to this treatment for wet age-related macular degeneration, where initial vision improvements fade over time, these results are quite favourable.”
“This five-year study tells us a lot about what’s happening with retinal vein occlusion patients in the real world,” said Dr Scott. “Prior to this study, retinal vein occlusion was widely considered an acute illness. This study shows that RVO is a chronic disease. It also underscores the importance of disease monitoring and individualised treatment to achieve the best possible vision.”
Source: NIH/National Eye Institute
