Purpose: Previous studies have documented that elevated plasma homocysteine level is a risk factor for vascular disease. This study was performed to determine whether hyperhomocysteinemia is a risk factor for central retinal vein occlusion.
Methods: In a case-control study, data from 74 patients with documented central retinal vein occlusion were reassessed. Control subjects consisted of individuals referred to the same clinic for assessment of a nonretinal vascular disease. Hyperhomocysteinemia was defined as a total plasma homocysteine level above the 95th percentile in the control group.
Results: The mean total plasma homocysteine level was 11.58 +/- 4.67 micromol/l (range, 5-26 micromol/l) for cases, and 9.49 +/- 2.65 micromol/l (range, 5-20 micromol/l) for control subjects. Of the 74 patients with a central retinal vein occlusion, 16 (21.6%) had total plasma homocysteine levels above the 95th percentile in the control group (odds ratio, 6.53; 95% confidence interval, 1.81-23.50; P =. 003). Hyperhomocysteinemia was present in five (55%) of the nine individuals with bilateral disease, nine (30%) of the 30 patients with ischemic occlusions, and 45 (31%) of the 83 eyes with severe visual loss.
Conclusion: Hyperhomocysteinemia is a risk factor for central retinal vein occlusion and may suggest a poor prognosis in patients with central retinal vein occlusion.