Retinal Oxygen Supply and Macular Pigmentation

Abstract

THERE is little doubt that the macular and foveal region of the human retina is lacking in blood vessels detectable by histological means¹. By subjective observation of the red corpuscles in blue light, Weale² has recently confirmed Gescher's estimate of 1° 30" for the visual angle within which the vessels of the central artery of the retina are absent. We have been unable to find any evidence that capillaries enter the foveal region from the choroidal vessels, and so it seems that in the absence of an oxygen supply directly from the blood, this region would tend to exhibit a relative anoxia. Hence, if the oxygen tension in the blood is reduced, a disturbance of central rather than peripheral vision is to be expected. In fact, experiment shows precisely the opposite effect, namely, a sparing of the central area and loss of function at the periphery under conditions of lack of oxygen^3,4.