Arterial occlusion associated with a prepapillary vascular loop. Anatomical changes on the long term follow up. / Oclusión arterial asociada con un asa vascular prepapilar. Cambios anatómicos en el seguimiento a largo plazo.

We report the case of a 13-year-old patient who complains of an acute superior visual field scotoma in the last 48hours. Best corrected visual acuity (BCVA) was 20/20 in both eyes. The right eye fundus examination revealed torsion of a prepapillary loop in the inferior branch of the retinal artery, associated with a arterial vascular attenuation and whitenning of the inferior retina that involved both nasal and temporal branches but spared the foveal region. During the follow-up the vascular loop dissapeared and only glial tissue was seen in front of the optic nerve head. BCVA remained 20/20 in both eyes. This report shows the evolution of the vascular loop after an occlusion. The absence of blood flow produces a collapse of the arterial walls, in time the vascular loop is replaced by glial tissue.