Retinal vein occlusion and transient monocular visual loss associated with hyperhomocystinemia

To report a 24-year-old man with bilateral central retinal vein occlusions who had preceding episodes of prolonged transient monocular visual loss during which ophthalmoscopic findings were not suggestive of vein occlusion.

Case report.

Extensive hematologic studies for causes of vein occlusion were unremarkable with the exception of increased plasma homocysteine in the patient and in his asymptomatic father.

Impending vein occlusion should be considered in the differential diagnosis of transient monocular visual loss regardless of ophthalmoscopic appearance, and hyperhomocystinemia should be considered as a possible cause of retinal vein occlusion.