Figure 1. Derivation of RGC Volume.

In a prior study we obtained OCT images through the fovea along the horizontal and vertical meridians out to 25° radial eccentricity from each of 42 subjects. These images were of sufficient quality to allow segmentation of the ganglion cell layer (red lines) from the inner plexiform layer. The axial length of the eye was also measured, and a model of eye biometry was then used to estimate the total volume of retinal ganglion cell tissue.