APRERETINAL vascular loop, or vascular loop in the vitreous, occurring in an otherwise normal fundus and participating in the blood supply of that fundus is a congenital vascular anomaly that is uncommon and distinct from remnants of the hyaloid artery. The terms prepapillary or preretinal artery (or vein) and vascular or spiral loops in the vitreous have been used interchangeably in the literature to describe this condition.
Such loops in the vitreous are most commonly arterial and unilateral, although they may be venous and, more rarely, bilateral. They arise from one of the main branches of the central retinal vessel.
These vascular loops may have various shapes, sizes, and forms; they may project a short way into the vitreous or very far. These loops are frequently accompanied by a thin glistening veil of connective tissue, which has variously been described as (a) remnants of the supportive tissue of the hyaloid