Plasma Homocysteine, Serum Folic Acid, Serum Vitamin B12, Serum Vitamin B6, Mthfr And Risk Of Pseudoexfoliation Glaucoma: A Meta-analysis

Background: The aim of this meta-analysis is to explore the relation betweenplasma total homocysteine (tHcy) levels, serum folic acid, vitamin B12andvitamin B6levels, methylenetetrahydrofolate reductase (MTHFR) C677Tgenotype and risk of pseudoexfoliation glaucoma (PEXG).Methods: A systematic search of EMBASE and PubMed of relevant articleswas carried out for all published articles. Main outcome measures included thecalculation of plasma tHcy levels, serum folic acid, vitamin B12and vitamin B6levels mean difference and odds ratios (OR) of MTHFR C677T genotypebetween cases and controls.Results: There were14studies for tHcy (485cases and456controls),5studiesfor folic acid (188cases and189controls),6studies for vitamin B12(199cases and225controls),3studies for vitamin B6(128cases and130controls) and8studies for MTHFR (479cases and661controls). Overall, the mean plasmatHcy levels in cases was3.38μmol/L (95%confidence intervals (CI):2.35–4.42)higher than in controls. Serum folic acids, but not vitamin B12and vitamin B6levels, was significantly lower in cases when compared with controls; Theweighted mean difference with95%CI were-1.50μmol/L (-2.53,-0.46),-36.29μmol/L (-81.27,8.68) and-0.60μmol/L (-2.55,1.35), respectively. There was noevidence of association between the MTHFR C677T genotype and PEXG (OR=1.28,95%CI:0.85,1.93).Conclusions: PEXG is associated with elevated plasma tHcy and low serumfolic acid levels but not serum vitamin B12, vitamin B6levels and MTHFRC677T genotype.