Oxygen metabolism in age related macular degeneration

Abstract

AbstractPurpose To determine whether oxygen saturation in retinal vessels of patients with age‐related macular degeneration (AMD) is different from that of a healthy population.Methods The non‐invasive retinal oximeter is based on a fundus camera. It simultaneously captures images of the retina at 600 nm and 570 nm and estimates retinal vessel oxygen saturation. Mean oxygen saturation of hemoglobin was measured in retinal arterioles and venules of 28 individuals with AMD, 6 were males. Eight patients had early AMD in at least one eye, 8 patients had untreated exudative AMD in at least one eye, and 12 patients had early AMD in one eye and untreated exudative AMD in the other eye. The age of AMD patients was 78 ± 9 years (mean ± SD) compared to 66 ± 4 years for the healthy controls (n=26).Results Oxygen saturation of hemoglobin in arterioles, after adjusting for vessel width, was 94.3 ± 3.7% in the healthy population compared to 93.5 ± 3.1% in early AMD (n= ;p=0.42) and 93.7 ± 3.8% in exudative AMD (n= ;p=0.55). The corresponding values in venules were 60.9 ± 5.6% in healthy eyes compared to 64.9 ± 7.0% in exudative AMD (p=0.017). In eleven patients with early AMD in one eye and exudative AMD in the other eye, oxygen saturation in arterioles was 93.5 ± 3.0% and 92.4 ± 2.8% (p=0.52) and in venules 66.3 ± 4.9% and 64.4 ± 5.3% (p=0.080).Conclusion Oxygen saturation in venules in exudative AMD is higher than in healthy controls and there is a similar trend in early AMD. Arteriovenous difference is smaller in AMD subjects than normals. The study suggests that retinal oxygen metabolism is affected in AMD. Commercial interest