Glaucoma refers loss of retinal ganglion cells in a characteristic pattern of optic neuropathy usually associated with increased intraocular pressure.

Blindness is the condition of lacking visual perception defined as a profound reduction in visual perception. On the 6m visual acuity scale, blindness is defined as less than 3/60. On the 20ft visual acuity scale, blindness is defined as less than 20/400. On the decimal visual acuity scale, blindness is defined as less than 0.05. Blindness is typically characterized by a visual field of no greater than 10 degrees in radius around central fixation.

Any abnormality of the electrical responses of various cell types in the retina as measured by electroretinography.

Macular dystrophy is a nonspecific term for premature retinal cell aging and cell death, generally confied to the macula in which no clear extrinsic cause is evident.

Atrophy of the choroid and retinal layers of the fundus.