To report a case of central retinal vein occlusion caused by iron deficiency anemia in a healthy young adult.

A 23-year-old female was referred to the department of ophthalmology after 4 days of acute onset of decreased vision in her left eye. The best corrected visual acuity was 20/20 in the right eye and 10/20 in the left eye. There was no ocular pain, afferent pupillary defect or other ocular symptoms. Results of the anterior segment examination were normal. Fundus examination showed mild optic disc swelling, flame-shaped retinal hemorrhages around the optic disc, and vascular tortuosity with dilatation. The fluorescein angiography showed tortuous peripapillary veins, multiple blocked fluorescences due to retinal hemorrhages, and delayed arteriovenous transit time. All medical examinations and laboratory tests for the risk factors of central retinal vein occlusion were within normal limits, except for iron deficiency anemia. The patient was subsequently treated with oral iron. Three months after the first visit, the best corrected visual acuity was 20/20 in the patient's left eye with nearly normal fundus appearances and no iron deficiency anemia detected in laboratory tests.

In cases of CRVO in young adults without other systemic diseases and risk factors, evaluation of the hematologic state may be necessary.