STOCKHOLM — A real-world analysis of retrospective data showed that administering more anti-VEGF injections over a 5-year time span to treat macular edema secondary to retinal vein occlusion (RVO) was associated with greater improvements in visual acuity. The research team concluded that this demonstrates a need for more durable treatments and long-term monitoring to maintain vision.
The findings were presented here at the American Society of Retina Specialists (ASRS) 2024 Annual Meeting.
Christiana Dinah, MBBS, MRes, London North West University Healthcare NHS Trust, London, United Kingdom, explained that RVO is a significant cause of visual impairment and is the second most common retinal vascular disorder. Its prevalence is expected to increase in the future due to ageing populations and a rise in cardiovascular disease.
"We know that there is very limited data in terms of the long-term outcomes with treatment of retinal vein occlusion," she said. "Our study analyzed the anti-VEGF treatment patterns for macular edema secondary to retinal vein occlusion in the UK and visual outcomes in this population over 5 years."
The Study
In this retrospective, observational study, investigators used Medisoft electronic health record data from 2013 to 2023 that were collected by 16 UK National Health Service trusts.
The investigators included patients with macular edema secondary to branch RVO (BRVO), central RVO (CRVO), or hemi-RVO (HRVO). Included patients had received at least one intravitreal anti-VEGF injection on or after diagnosis, had visual acuity measured at index injection, and had 3-60 months of follow-up after index injection.
A total of 3511 eyes from 3465 patients with BRVO and 3568 eyes from 3514 patients with CRVO or HRVO were included in the analysis. More than half (57.4%) of the eyes were monitored for at least 24 months, with 19.1% followed for a longer duration of 60 months following the index injection.
During the first 6 months, BRVO eyes received an average of 4.3 anti-VEGF injections, whereas CRVO and HRVO eyes received 4.1 injections, indicating a high frequency of treatment in the early phase.
However, this frequency decreased in the subsequent 6 months, with BRVO eyes receiving an average of 2.1 injections and CRVO and HRVO eyes receiving 2.0 injections. ​​Over the years, the mean number of injections continued to decline. In the second year of follow-up, BRVO and C/HRVO eyes received 3.4 and 3.2 injections, respectively, which fell to 2.5 and 2.4 injections during the fifth year of follow-up.
More Is Better
Visual acuity changes were also tracked, showing a mean improvement of 11.1 Early Treatment Diabetic Retinopathy Study (a test used to measure the visual acuity of patients who suffer from low vision) letters for BRVO and 13.8 letters for CRVO and HRVO at 3 months post injection, which decreased to 8.3 and 7.0 letters by month 60.
"We saw rapid and substantial visual gain within 3 months," she said. "This was stable until about 18 months, when it started to reduce. In the CRVO cohort, the visual gain by year 5 is at least half what it initially was."
The investigators noted that those who received fewer injections exhibited less improvements in visual acuity. Mean changes at month 12 for low (< 4), medium (4-8), and high (> 8) injection groups showed a trend: Higher injection numbers correlated with better visual outcomes, emphasizing the importance of consistent treatment in optimizing vision recovery, Dinah explained.
Elucidating Results With a Caveat
Yasha S. Modi, MD, a vitreoretinal surgeon at New York University in New York City who moderated the Retinal Vascular Disease Symposium 2 panel discussion at ASRS24, commented that a major limitation of the study is the loss of follow-up data.
"When you have the data looking at 3500 patients to start and then by 60 months you are down to 500 patients, you only have about 15% of your original data set," he said, wondering how the selection bias affected the interpretation of the results.
"We have to take these results with that caveat," Dinah said. She added that the study results must be read in combination with the fact that randomized control trials show higher vision gain when patients receive injections every 4-8 weeks rather than every 3 months. "That suggests that the number of injections does matter, and we need more durable treatments to maintain the initial vision gain."
Dinah has declared interests with Ora Clinical, Boehringer Ingelheim, Topcon, Apellis Pharmaceuticals, Janssen, Roche, and AbbVie.
Yasha Modi has declared interests with Notal Vision, ZEISS, Apellis Pharmaceuticals, Alimera Sciences, Alcon, AbbVie/Allergan, Iveric Bio, DORC, EyePoint Pharmaceuticals, Genentech, Regeneron Pharmaceuticals, and Théa.
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