Hypoxia in Human Central Retinal Vein Occlusion

Abstract

 

Purpose:

 

To non-invasively measure oxygen saturation in retinal vesselsin patients with central retinal vein occlusion (CRVO).

 

Methods:

 

The retinal oximeter is composed of a fundus camera, beam splitterand a digital camera. It yields fundus images with isosbesticand non-isosbestic wavelengths of light simultaneously. Custom-designedsoftware analyzes the images and estimates oxygen saturation.Measurementswere made on 5 individuals with CRVO. Oxygen saturation wasmeasured in 1^st and 2^nd degree vessels within 2 disc diametersfrom the optic disc. Mean saturation levels were calculatedfor each eye and paired t-tests were used for statistical analysis.

 

Results:

 

The table below summarizes the oxygen saturation measurementsand statistical analysis.Variabilityin venous oxygen saturation within eyes is considerable, assome venules show near normal levels of oxygen saturation (seeimage below).  

 

 

Conclusions:

 

Variable levels of hypoxia were observed in retinal venulesin patients with CRVO. Mean venous oxygen saturation is lowerin CRVO affected eyes than in fellow eyes, but differences inarterial saturation are not significant.

 

Keywords: vascular occlusion/vascular occlusive disease • oxygen • imaging/image analysis: clinical