Bilateral Congenital Prepapillary Retinal Arterial Loop.

Prepapillary vascular loops are rare congenital vascular abnormalities of the retinal vasculature. This mostly benign condition can sometimes cause complications such as branch retinal artery occlusion and vitreous haemorrhage. Disc collaterals, neovascularisation of the optic disc, idiopathic retinal vasculitis, aneurysms and neuroretinitis (IRVAN) syndrome and Wyburn Mason syndrome should be kept in mind for the vascular differential diagnosis. In addition, when the loops present bilaterally and settle into the region adjacent to the optic disc border, they can be misdiagnosed as papilloedema. The diagnosis is usually made clinically by careful fundus examination. Optical coherence tomography and fundus fluorescein angiography might serve as ancillary tools for the diagnosis. In this report, we present a 52-year-old male with bilateral prepapillary arterial loops referred to our clinic with a preliminary diagnosis of papilloedema.