Diagnostic imaging of retinal disease has been limited to structural analysis, angiography and testing of visual function. Until the advent of retinal oximetry, no metabolic retinal imaging has been available in the clinic. Metabolic imaging has obvious relevance to metabolic disease such as diabetic retinopathy and oxygen imaging is particularly appropriate for ischemic disease such as retinal vein and artery occlusion. Fundus camera based spectrophotometric retinal oximeters have allowed clinical studies over the last several years. Remarkably, abnormalities in retinal oxygen metabolism have been discovered in most major retinal diseases, including diabetic retinopathy, retinal vein occlusions, glaucoma and age related macular degeneration. These results open a new window into the pathophysiology of these diseases and may help evaluate severity and progression.