Relation of oxygen saturation to stage of diabetic retinopathy

SummaryAimTo assess whether oxygen saturation of the retinal vessels is related to degree of diabetic retinopathy.MethodsA prospective study included 114 eyes of 76 patients with diagnosed diabetes and 57 eyes of 29 non diabetic patiens. The diabetic patients were divided into groups according to severity of the retinopathy.ResultsIn healthy controls mean arterial saturation was 96.5 ± 2.6%, mean vein saturation was 62.3 ± 7.4% and A-V difference was 34.3 ± 7.2%. In diabetic patients with no retinopathy mean arterial saturation was 96.5 ± 3.2%, mean vein saturation was 66.3 ± 6.3% and A-V difference was 30.2 ± 4.9%. In patients with mild diabetic retinopathy mean arterial saturation was 96.7 ± 4.6%, mean vein saturation was 67.9 ± 7.2% and and A-V difference was 28.8 ± 8.2%. In patients with moderate nonproliferative retinopathy mean arterial saturation was 97.8 ± 4.6%. mean vein saturation was 69.9 ± 6.7% and A-V difference 27.9% ± 5.8%. In patients with severe non-proliferative and proliferative retinopathy mean arterial saturation was 100.5 ± 5.6%, mean vein saturation was 74 ± 7.2% and A-V difference was 26.5 ± 7.8%.ConclusionWe confirmed an increase in oxygen saturation in both retinal artery and vein in relation to degree of diabetic retinopathy.