Cystoid Macular Edema Associated With Venous Stasis in a Patient With Previously Undiagnosed Hyperhomocysteinemia

A 74-year-old female patient visited our department reporting unilateral painless vision reduction in her left eye noticed a few months ago. Clinical examination revealed decreased visual acuity in the left eye. Fundoscopy showed bilateral retinal venous stasis with cystoid macular edema in the affected eye, also confirmed by optical coherence tomography (OCT) imaging. OCT angiography showed no evidence of ischemia. Bilateral findings raised suspicion for a systemic underlying cause. Laboratory tests showed elevated homocysteine plasma levels. Brain MRI showed ischemic encephalopathy. Hyperhomocysteinemia creates a hypercoagulable state and therefore it is a risk factor for vascular thrombosis and retinal vein occlusion. Our patient was considered to suffer from an impending retinal vein occlusion due to venous stasis, causing a persistent macular edema, and, therefore, was treated with anti-vascular endothelial growth factor (VEGF) injections. She was also prescribed oral folic acid for life. Her visual acuity showed improvement and remained stable for a long period of time. When macular edema reoccurred she was treated with another intravitreal injection.