Abstract
Abstract: :
Purpose:The role of elevated homocysteine (Hcy) in retinal vein occlusion is still unresolved. We explored the relationship between the MTHFR polymorphism, tHcy and B-group vitamin status in subjects presenting with retinal vein occlusion and compared them with age- and sex-matched healthy controls Methods:One hundred and thirty one subjects gave consent and entered the study (70 controls and 61 cases). The age, gender, smoking habit, cardiovascular status were noted and dilated fundus examination performed on both eyes. Total plasma Hcy (tHcy), serum B12 and folate were measured by HPLC, MTHFR genotype was ascertained following PCR amplification by polyacrylamide gel electrophoresis of the amplified product. The relationship between plasma homocysteine and genotype was explored using univariate analysis and chi-squared tests used to compare genotype and allele distribution between cases and controls. Results:Cases and controls were well matched for age and gender. A history of hypertension (p=0.06) and exposure to cigarette smoking (p=0.02) was more frequently recorded in cases compared with controls. Mean tHcy and serum B12 and folate did not differ significantly between cases and controls. The frequency of the thermolabile allele was not significantly different between cases and controls (37.5% in cases and 37.7% in controls) and there was no evidence of departure from Hardy Weinberg equilibrium. Univariate analysis of variance showed that genotype was a significant predictor of tHcy status (p=0.014). From the analysis conducted in the present study the predicted difference in tHcy between thermolabile homozygotes and non-thermolabile homozygotes was 4.0 mmol/l (SE 1.419, p=0.006). Conclusion:Neither plasma homocysteine not MTHFR genotype were risk factors for retinal vein occlusion in this study.
Keywords: 355 clinical (human) or epidemiologic studies: risk factor assessment • 615 vascular occlusion/vascular occlusive disease • 554 retina