Abstract
Purpose :
To determine role of oximetry in calculating oxygen saturation in cases with optic disc edema and establishing correlation with visual field defects
Methods :
Twenty consecutive eyes diagnosed to have disc edema secondary to various pathologies diagnosed on basis of clinical examination underwent non-invasive dual wavelength photo-spectrometric imaging of the retina (Oxymap T1, Oxymap hf, Reykjavik, Iceland) to determine the oxygen saturation in the retinal vessels and their diameters. They also underwent standard automated perimetry on the Humphrey Field Analyzer (HFA™,Carl Zeiss Meditec) The retinal oximetry values obtained were compared with age matched normals and also correlated with mean deviation on automated perimetry
Results :
Arteriolar diameters were reduced and venous diameters were increased in the affected eyes. Arteriolar saturations were increased, venous saturations were decreased and arterio-venous saturation difference (AVSD) was increased as compared to the age matched normals. Significant positive correlation has been noted between arteriolar saturation and mean deviation
Conclusions :
Decreased arteriolar diameters and increased venous diameters suggest stasis possibly due to the increased pressure due to optic nerve head edema. This may result in increased arterio-venous transit time thus allowing more time for oxygen exchange. This could possibly explain the increased arterio-venous saturation difference. Oximetry may be useful in the screening and quantifying the imapct of disc edema on visual function in patients with disc edema
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.