A number of patients afflicted with multiple sclerosis present on ophthalmoscopic examination a peculiar white sheathing of some of their retinal veins. In certain instances it appears as a thickening of the walls of the veins, especially in their peripheral branches. In other instances it takes the form of small white plaques overlying the veins, and there occasionally may be a constriction in caliber of the lumen.1
In the normal retina the walls of the blood vessels are transparent and therefore invisible. Only the column of blood within them is seen by the examiner. On the head of the optic nerve an excess of supporting tissue may at times form white cuffs around the vessels. When these cuffs are limited to the optic disk they are merely developmental anomalies. When they extend beyond the margins of the disk they indicate the previous presence of an inflammatory reaction or papilledema,