Purpose: To evaluate total plasma homocysteine level during the acute phase of central retinal vein occlusion (CRVO) compared with a matched healthy group in Iranian population, and determine whether hyperhomocysteinemia is also a risk factor for CRVO.

Methods: A study group contains 54 patients presenting with CRVO in recent one month, acute phase of the decease, was compared for fasting total plasma homocysteine level with a matched control group of 51 patients evaluated in the same clinic for a non retinal disease diagnosis.

Results: The mean total plasma homocysteine level was 14.76±7.67 μmol/l in cases, and 11.42±3.74 μmol/l in control subjects. It shows a significant difference (p=0.005) in mean plasma homocysteine level between the cases and control group. Odds ratio of CRVO for individuals with hyperhomocysteinemia was 2.88 (95% CI=1.08-7.71 and p=0.03). The overall multivariable-adjusted odds of CRVO in participants with plasma homocysteine level above 15 μmol/l was 4.71 (95% CI=1.46-15.19 and p=0.009) Hyperhomocysteinemia was not statistically different in each age group (<60 years: 27%, 61-70 years: 33.3 %, 71-80 years: 31.6%, >81 years: 33.3%,
Chi-square test, p=0.98)

Conclusion: Elevated total plasma homocysteine level is an independent risk factor for CRVO in Iranian population. In addition to an evaluation of all conventional cardiovascular risk factors, measurement of total homocysteine for evidence of hyperhomocysteinemia may be important in the initial investigation and management of patients with CRVO.