1. A method for detecting and monitoring an optic neuropathy of a retina, comprising: obtaining imaging data of a region of the retina; identifying boundaries between layers of the retina in the region based on the imaging data; and determining, on a location-by-location basis for at least a portion of the region of the retina, a measurement value related to ratio value (R) between a total backscattered signal intensity of one or more target layers of the retina and a total backscattered signal intensity of one or more reference layers to generate a set of measurement values for locations in the portion of the region of the retina, wherein the measurement value is generally monotonic with respect to an integrated attenuation value (μ ATT d) such that R is used as a proxy measurement for μ ATT d, which is determined according to the following relation: μ ATT ⁢ d = log ⁡ ( R / β + 1 ) 2 , where β is modeled as a substantially constant value, R is the ratio value, and μ ATT d represents a total attenuation of light over a depth d of the retina.