Macular degeneration. Optical coherence tomography (OCT) scan of a section through the retina of the eye of a patient with age-related macular degeneration (AMD). The retina is the light-sensitive layer lining the inner surface of the eye that contains the rod and cone cells. The macula (centre) is the central area of the retina that contains the highest density of these cells. Degeneration of the macula results in the loss of site in the central field of vision. It is a major cause of blindness and visual impairment in older people.