A 44-year-old man with primary pulmonary hypertension was referred for a possible carotid-cavernous fistula. Since initiation of epoprostenol therapy 3 months prior to presentation, he noticed progressive redness in both eyes and a macular rash, primarily involving the face and abdomen. Examination revealed engorged superficial conjunctival vessels in both eyes. Magnetic resonance imaging and angiography of the brain and orbits revealed no evidence of an arteriovenous fistula. Epoprostenol, a vasodilator, was associated with dilated conjunctival vessels in this patient.