Optic neuritis
Inflammation involving the nervehead typically causes swelling and elevation of the nervehead. If the nervehead reaction is particularly intense, the swelling slides into the adjacent retina. Neurological diseases of several types — such as multiple sclerosis — can be responsible for the nervehead swelling. Closure of a nutrient blood vessel within the nervehead as a result of hypertensive arteriosclerosis can also cause transient congestion of the nervehead.
