Normative Database of Retinal Oximetry in Asian Indian Eyes

Abstract

ObjectiveTo study the oxygen saturation profile in normal Asian Indian eyes.DesignA cross sectional prospective study.SubjectsNinety eight consecutive patients presenting to our hospital with best corrected distance visual acuity (BCVA) of 20/20 and a normal ophthalmic examination were included in the study. Patients having any ocular or systemic disease were excluded from the study.Materials and MethodsOximetry was performed on all subjects with the Oxymap T1 retinal oximeter (Oxymap hf, Reykjavik, Iceland).Main Outcome MeasuresThe images were analysed for oxygen saturation and diameter.ResultsThe mean age was 33 years (Range: 18-63; SD: 12.4). The average arteriolar saturation was 90.3 ± 6.6% and the venous saturation was 56.9% ± 6.3. The average A-V (arterio-venous) difference was 33.2% ± 5.2. There was an increase in arteriolar (R2 = 0.264; p=0.001) and venous saturation (R2 = 0.151; p=0.001) with age. There was no significant change in the arterio-venous saturation difference (AVSD). The inferotemporal quadrant had the lowest saturations. Age correlated positively with ocular perfusion pressure (OPP)(R2 = 0.07; p=0.007). OPP correlated positively with global arteriolar saturation (R2=0.057, p=0.018).ConclusionThis study provides the normative database for an Indian population and is comparable to previous studies. Age, vessel diameter and OPP were the significant factors that influenced the saturation. Arteriolar and venous saturations increased with age while the AVSD did not change significantly.

Relationship between oxygen saturation of the retinal vessels and visual field defect in glaucoma patients: comparison with each hemifield

“…Due to advancements in the spectrophotometric retinal oximeter technology, this has made it possible to develop new ways to non-invasively measure retinal SaO 2 . In contrast, both males and females in the Indian population exhibited increases in the venous SaO 2 with age (Mohan et al 2015). In contrast, both males and females in the Indian population exhibited increases in the venous SaO 2 with age (Mohan et al 2015).…”

“…A study that evaluated the venular oxygen saturation in accordance with age in a Caucasian population reported finding a significant decrease along with a significant increase in the arteriovenous difference (Geirsdottir et al 2012). Mohan et al (2015) examined the same association in an Indian population and demonstrated that there was increased venous oxygen saturation in accordance with the age. It has also been shown that higher SaO 2 measurements are associated with narrower retinal vessels (Hammer et al 2008) and that increased arteriolar SaO 2 is correlated with higher ocular perfusion pressures (Geirsdottir et al 2012).…”

“…For example, a study using this methodology reported that Caucasian males exhibit significant decreases in the venous SaO 2 in accordance with age, with a similar trend found in females (Geirsdottir et al 2012). In contrast, both males and females in the Indian population exhibited increases in the venous SaO 2 with age (Mohan et al 2015). Therefore, the exact influence of ageing on the venous SaO 2 remains unknown.…”

Retinal oximetry and systemic arterial oxygen levels

“…In contrast to the above studies, Mohan et al. () found the arteriolar and venous oxyhaemoglobin saturation to increase with age but the AV‐difference to remain unaffected. There was no statistical correlation between the retinal oximeter measurements and finger pulse oximetry readings.…”

Retinal oxygen saturation before and after glaucoma surgery

“…; Mohan et al. ). The previously noted differences between our current study and the Hardarson et al.…”