Estimation of retinal vascular oxygen tension using phosphorescence lifetime imaging

Availability of oxygen is important for normal metabolic function of the retinal tissue. An abnormality in the level of retinal oxygenation is potentially an important cue to the onset or presence of some common retinal diseases. It is therefore important to accurately estimate of oxygen tension in retinal vessels and this research addresses the problem of improved estimation from data acquired with phosphorescence lifetime imaging.;In past work oxygen tension was obtained using the classical least squares estimate of intermediate variables whose noise-contaminated linear combinations were observed as phosphorescence intensity images. The least squares method produces high variance estimates of oxygen tension that are outside of the physiological range, impeding a reliable analysis of retinal oxygenation. Accurate estimation of oxygen tension in retinal capillaries is challenging as the noise and experimental uncertainties have more pronounced effect on microvasculature imaged with available resolutions.;Methods of improved estimation of oxygen tension in large retinal vessels and retinal capillaries from phosphorescence lifetime imaging data are proposed in this dissertation to overcome the limitations of methods used in past work. The effectiveness of the proposed methods was demonstrated by applying it to simulated data as well as image data acquired from rat retinas.