Purpose:
To study in-vivo retinal oximetry using snap shot hyperspectral retinal imaging using computerized tomographic spectrometry ( CTIS) in healthy subjects and patients with retinal vascular disease.
Methods:
5 patients and 5 healthy subjects were enrolled. Patients had either central or branch retinal vein occlusions. Patients who underwent treatment had repeat oximetry imaging on their follow up visits. Three wavelength oximetry and Lambert Beer formula was used to analyse the oximetry data.Oximetry maps were generated for each subject, both at the macula and optic nerve.
Results:
Our software algorithm was able to differentiate arterioles from venules in normal subjects at the optic nerve head, with an average 35% difference in relative oxygen saturation between the two vascular channels. Macular maps in patients with vascular occlusions showed various degrees of oxygen saturation, which appeared to topographically map to areas of collateral formation. Patients with longstanding vascular occlusions showed patterns of oximetry distribution, which varied depending on the pattern of collateral formation.
Conclusions:
Snap-shot hyperspectral retinal oximetry has the potential to provide in vivo functional maps of the retina and retinal vasculature. Further refinement of our software algorithm is underway, as well as enrollment of additional patients.
Keywords: imaging/image analysis: clinical • ischemia • vascular occlusion/vascular occlusive disease