Purchase this article with an account.
S. H. Hardarson, R. A. Karlsson, G. H. Halldorsson, S. Basit, T. Eysteinsson, J. A. Benediktsson, J. M. Beach, A. Harris, E. Stefansson; Increased Oxygen Saturation After Laser Treatment in Human BRVO. Invest. Ophthalmol. Vis. Sci. 2007;48(13):297.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Earlier animal studies have indicated that branch retinal vein occlusion (BRVO) leads to retinal hypoxia and that the hypoxia may be reversed by laser treatment. In this study we measure the hemoglobin oxygen saturation (SatO2) in retinal venules in patients with BRVO before and after scatter laser photocoagulation.
The retinal oximeter is composed of a fundus camera, beam splitter and a digital camera. It yields fundus images with isosbestic and non-isosbestic wavelengths of light simultaneously. Custom-designed software analyzes the images and estimates SatO2. Measurements were made on 14 individuals with BRVO. Five were measured both before and after laser treatment. Cases of hemivein and central retinal vein occlusion (CRVO) were also measured. Paired t-test was used for analysis.
In affected venules in BRVO patients the saturation was 45±10% before laser treatment and rose to 53±6% after treatment (p= 0.041, n=5, see figure). Hemivein occlusion showed a stepwise increase in saturation after repeated laser treatment sessions and similar findings were seen in CRVO.
The retinal oximeter measures an increase in hemoglobin oxygen saturation following laser treatment for BRVO. This is in agreement with earlier studies on animals. Oximetry may provide an immediate physiological measure of the effect of laser treatment. The oxygen improvement preceeds the structural and clinical effect by weeks and may allow the ophthalmologist to better determine how much photocoagulation is necessary.
This PDF is available to Subscribers Only