An increasing body of evidence is supporting the role of nitric oxide (NO), a potent microcirculatory regulator, in the pathogenesis of ocular disorders. Within the posterior segment, NO is capable of dilating retinal and choroidal vessels down to the capillary level by relaxation of pericytes.1
Niacin (nicotinic acid), an established treatment for dyslipidemia, generates NO synthase, and ultimately NO, through a prostaglandin-mediated process.2 Recently, Abrishami et al3 reported the effects of niacin therapy on improving venous outflow in retinal vein occlusion (RVO) secondary to the compound’s vasodilatory properties. Herein, we present a case of macular RVO with chronic cystoid macular edema (CME) associated with resolution by use of systemic niacin therapy, including the reversibility of this effect when the patient stopped using the medication.