Changes in retinal arteriolar oxygen saturation predict disease activity in patients treated with aflibercept for neovascular age‐related macular degeneration

Abstract

PurposeIn order to individualize treatment, it is important to identify non‐invasive markers for disease activity in patients with neovascular age‐related macular degeneration (nAMD). In this prospective study we aimed to investigate changes in retinal oxygen saturation in patients with nAMD before and after initial aflibercept therapy.MethodsSixty‐six eyes diagnosed with nAMD were included. All patients received three monthly injections with 2.0 mg aflibercept and were then divided into responders and non‐responders according to post‐treatment disease activity. Non‐responders by definition had loss of ≥5 ETDRS letters or residual retinal edema (based on spectral domain‐OCT) or macular hemorrhage. Retinal oximetry (Oxymap T1, Oxymap, Reykjavik, Iceland) was performed at baseline and follow‐up, and images were graded by a trained grader.ResultsAt baseline, mean age was 80.0 years and 62.1% were women. Thirty‐six of 66 patients (54.5%) were non‐responders, and these were younger (77.8 vs. 82.8 years, p=0.01) and trended towards a higher increase in retinal arteriolar oxygen saturation from baseline to follow‐up (+1.0% vs. +0.1%, p=0.06). In a multiple logistic regression model, adjusted for sex, age, diabetes and smoking, each 1%‐point increment in retinal arteriolar oxygen saturation from baseline to follow‐up was independently associated with a lower chance of full treatment response (odds ratio 0.78, 95% confidence interval 0.62‐0.98, p=0.036). Retinal venular oxygen saturation did not associate with pre‐ or post‐treatment disease activity.ConclusionsRetinal oxygen saturation may be a promising marker for disease activity in nAMD. Increasing retinal arteriolar oxygen saturation in response to initial intravitreal aflibercept therapy associates with a 22% lower chance of full treatment response after initial aflibercept therapy.