Fundus of an Adult

The normal disc has clearly demarcated edges, although the nasal side may be slightly less clear-cut than the temporal side. The pink color of the disc is attributable to the papillary capillaries viewed against the fenestrated white sclera (lamina cribrosa). The "physiologic cup" is a central area where the nerve fibers and capillaries are relatively sparse. The main vessels enter (or emerge) on the nasal side of the physiologic cup. The arteries are distinctly lighter red than the veins and have only about two-thirds the diameter of the corresponding veins. The latter frequently pulsate at the point of emergence but the artery never pulsates under normal conditions. A cilioretinal artery coming from the choroid and entering at the temporal margin of the disc to supply a variable portion of the central area is frequently present, as in the present case. The macula seen at the extreme left of the photograph corresponds to the functional posterior pole of the eye; that is, it is the area of most acute vision. It is recognizable by a darker portion of the fundus and, when viewed directly with the ophthalmoscope, by a central point of reflected light that moves in a contrariwise fashion to the movement of the ophthalmoscope. Disease/ Diagnosis: Pigment epithelium of eye