Originally published by 2 Minute Medicine® (view original article). Reused on AccessMedicine with permission.

1. Fewer anti-VEGF intravitreal injections were required in the SRT group over 2 years.

2. Change in visual acuity was non-inferior in the SRT group compared to the sham group.

Evidence Rating Level: 1 (Excellent)

Study Rundown:

Neovascular age-related macular degeneration (nAMD) is a major cause of blindness, often treated with anti-vascular endothelial growth factor (anti-VEGF) agents through intravitreal injections. Ionizing radiation, such as stereotactic radiotherapy (SRT), may offer therapeutic benefits by targeting key pathogenic processes in nAMD. This randomized controlled trial aimed to determine if SRT could reduce the number of required anti-VEGF injections without compromising visual acuity. The primary outcome of this study was the number of intravitreal ranibizumab injections needed over two years, while the key secondary outcome was visual acuity measured by the Early Treatment Diabetic Retinopathy Study. According to study results, SRT significantly reduced the number of required injections without adversely affecting visual acuity compared to sham treatment. Although this study was well done, it was limited by the occurrence of microvascular abnormalities in some SRT-treated eyes.

In-depth [randomized controlled trial]:

Between Jan 1, 2015, and Dec 27, 2019, 610 patients were screened for eligibility across 30 UK hospitals. Included were patients ≥ 50 years old with pre-treated chronic active nAMD who had received ≥ 1 previous anti-VEGF injections. Altogether, 411 patients (241 in 16-Gy SRT and 118 in sham SRT) were included in the final analysis. The primary outcome of number of intravitreal ranibizumab injections required over 2 years was significantly greater in the sham SRT group compared to the SRT group (13.3 injections vs. 10.7 injections, 95% confidence interval [CI] -4.2 to -1.6, p<0.0001). Additionally, the secondary outcome of change in visual acuity was non-inferior between groups, with the SRT group showing an adjusted mean letter loss difference of -1.7 letters compared to the sham group. Findings from this study suggest that SRT can reduce the treatment burden of ranibizumab injections without compromising visual acuity.

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