What happens to the optic disc and retina in glaucoma?

In glaucoma there is a spectrum of disc damage ranging from highly localized tissue loss (a notch in the neuroretinal rim), vertically oval cupping, or simple concentric enlargement of the cup. The accompanying visual loss may likewise range from a well-localized nerve fiber bundle detect to a generalized depression. Cases with diffuse loss of axons, a concentric enlargement of the cup, and a generalized reduction in visual function are more difficult to recognize unless the previous state of the disc and vision is well documented or there is asymmetry between the two eyes.