Homocystinuria in a 14-year old girl manifesting as central retinal artery occlusion: A case report.

Central retinal artery occlusion (CRAO) is one of the causes of sudden loss of vision. Homocystinuria is an autosomal recessive inherited disorder and is characterized by increased levels of homocysteine in the urine and blood. We present a case of homocyistinuria in a 14-year girl, presenting as CRAO with a family history of vascular thrombotic events. The patient did not have any local predisposing factors or prior history of thromboembolic episodes. Left eye fundus examination revealed a pale retina with sparing of cilioretinal artery. On examination Visual acuity of the right eye was 6/6 and left eye was completely blind with no perception of light. Homocysteine level on admission was 34.60umol/l. Patient was started on Rivaroxaban 10mg, Vitamin B6 , Vitamin B12 and folic acid. On follow up examination after 2 months the visual acuity in the left eye was 6/9. The dramatic improvement in the visual acuity can be attributed to the sparing of the cilioretinal artery. Followup Homocysteine levels after two months of treatment was 12umol/l. Ophthalmologist should be aware of this rare manifestation of homocystinuria as CRAO as they can play an important role of diagnosing the underlying medical illness.