AIM: To explore the relation of homocysteine(Hcy)and its metabolic related indicators with primary angle-closure glaucoma(PACG).

METHODS: In this study, a total of 150 PACG patients and 150 controls were enrolled. The patients with PACG were diagnosed by applanation tonometer, Humphrey perimetry(HVF), optical coherence tomography(OCT), gonioscope. The normal controls were recruited from physical examination center. Blood samples were collected and the plasma was used to determine homocysteine, vitamin B12 and folic acid. DNA was extracted to determine the methylenetetrahydrofolate reductase(MTHFR)C677TT genotype and gene polymorphism.

RESULTS: There was a statistically significant difference(t=2.04,P=0.04)in mean homocysteine levels between patients with PACG(16.11±1.66μmol/L)and controls(15.74±1.52μmol/L). The level of vitamin B12 in PACG group was 248.09±119.07pg/mL and the control group was 230.21±142.93pg/mL. No statistically significant difference was found on the vitamin B12 level between the two groups(t=0.84,P=0.40). The folic acid levels showed no statistically significant differences(t=1.65,P=0.17)between the PACG group(12.02±7.81ng/mL)and the control group(13.15±6.25ng/mL). The frequency distribution of the MTHFR C677T genotypes was found to be significantly associated(χ²=6.2,P<0.05)with PCAG(CC 84.7%, CT 4.7%, TT 10.7%)as compared to the controls(CC 94.7%, CT 2.0%, TT 3.3%). The frequency distribution of TT genotypes of MTHFR C677T in the PACG group was significantly higher than that in the control group. Moreover, our findings showed significant difference(χ²=14.2,P<0.05)between the allele frequency of the C677T single nucleotide polymorphism within the MTHFR gene in POAG patients(T 87.0%, C 13.0%)and the control group(T 95.7%,C 4.3%).

CONCLUSION: These results show that the Hcy level and the TT genotypes of MTHFR C677T were higher in the PACG patients than in controls. Therefore, our data suggests that high Hcy level and the related indicators are associated with high PACG risk.