Spectral imaging of the retina

IntroductionThe work described here involved the use of a modified fundus camera to obtain sequential hyperspectral images of the retina in 14 normal volunteers and in 1 illustrative patient with a retinal vascular occlusion.MethodsThe paper describes analysis techniques, which allow oximetry within retinal vessels; these results are presented as retinal oximetry maps.ResultsUsing spectral images, with wavelengths between 556 and 650 nm, the mean oxygen saturation (OS) value in temporal retinal arterioles in normal volunteers was 104.3 (16.7), and in normal temporal retinal venules was 34.8 (17.8). These values are comparable to those quoted in the literature, although, the venular saturations are slightly lower than those values found by other authors; explanations are offered for these differences.DiscussionThe described imaging and analysis techniques produce a clinically useful map of retinal oximetric values. The results from normal volunteers and from one illustrative patient are presented. Further developments, including the recent development of a snapshot spectral camera, promises enhanced non-invasive retinal vessel oximetry mapping. © 2011 Macmillan Publishers Limited All rights reserved.