To the Editor. —Prepapillary vascular loops are well documented in the literature. 1-5 These lesions are believed to be congenital anomalies of the central retinal artery. We have observed prepapillary vascular loops in a mother and daughter. We postulate that there may be a hereditary component to this entity. Report of Cases. —Case 1. —This 33-year-old woman with mild myopia was evaluated at University Hospitals of Cleveland for a change in the prescription of her eyeglasses. Her best corrected acuity was 20/20 in each eye. Results of an external and anterior segment examination were normal. A fundus examination disclosed prepapillary vascular loops in each eye (Figs 1 and 2). On informing the patient of the presence of the prepapillary loops, she reported that her mother had similar findings. Case 2. —This 66-year-old woman (the mother of patient 1) had been followed up at the eye clinic of University Hospitals