A lenslet-based device for measuring oxygen saturation in the retina

Diabetic retinopathy (DR) is a complication of diabetes affecting up o 80% of all diabetic patients. DR can lead to blindness and reduced quality of life. Some authors have hypothesized that changes in the flow dynamics associated with DR as well as changes in retinal oxygenation can lead to macular edema. Measurements of oxygen saturation in the retina could help understand the real mechanisms behind this condition. We present a novel spectroscopic imaging device to measure oxygen saturation in the retina. Our system uses a lenslet array to spatially and spectrocopically divide a fundus image. A three wavelengths algorithm is used to calculate oxygen saturation in small vessels. Only wavelengths in the 500 - 580 nm range are considered in order to minimize the wavelength dependence of the scattering from erythrocytes. Preliminary testing on healthy subjects showed values of oxygen saturation comparable to the one reported in the literature.