Spiral looping of retinal artery.

An isolated retinal vascular anomaly in the form of an arterial loop is presented in a 32-year-old male. This loop originated on the retina beyond the optic disc border and returned to the lower branch of the central artery on the retinal tissue after making six spirals. The retinal circulatory dynamics of this eye, defined by fluorescein angiography, was observed over a period of 12 years with no loss of function to the involved eye.