The influence of age on retinal vessel oxygenation

Abstract Purpose To validate weather regional differences in retinal vessel oxygenation depend on age. Methods Fifty three healthy individuals (age range 19‐61 years; mean age 35 (SD 11) years) underwent manual sphygmomanometry, non‐contact tonometry (Keeler Pulsair, UK) and retinal vessel oxygen saturation measurements using dual wavelength oximetry (ImedosSystems, Germany). In order to analyse regional saturation differences, all vessels were grouped according to their location into major superior and inferior artery and vein as well as into macula and peripheral feeders (MF and PF respectively for arteries) and macula and peripheral drainers (MD and MF respectively for veins). Results Multiple regression analysis revealed no influence of age, blood pressure (SBP: 116 (13)mmHg, DBP:73 (11)mmHg) and intraocular pressure (12 (3)mmHg) upon arterial and venous oxygen saturation measurements (p>0.05). Superior and inferior MF, PF, MD and PD were comparable (MF: 97 (9)% and 97 (8)%, p=0.955; PF: 92 (11)% and 91 (9)%, p=0.607; MD: 87 (14)% and 85 (13)%, p=0.594; PD: 61 (14)% and 58 (16)%, p=0.381). MF and PF were significantly different in the superior and inferior retina (p=0.006 and p=0.0002) as were MD compared to PD (p<0.0001 and p<0.0001). Conclusion Regional variations in oxygen saturation of retinal arterioles and venules are independent of age, blood pressure and intraocular pressure.