1. A method of detecting glaucoma, comprising the steps of mapping at least a portion of the fundus of the eye by forming a plurality of pixels using light from a spectral image system, dividing each light beam from the light that is reflected from the fundus with an interferometer into two coherent beams, recombining the two coherent beams and detecting the interference, measuring the interference as a function of the optical path difference, comparing the intensity of the light to the optical path difference for each of the plurality of pixels, estimating the oxygen saturation level at each of the plurality of pixels, superimposing the fundus maps on maps of anatomic borderlines, and comparing portions of the superimposed fundus maps to predetermined fundus maps.