Purpose: To compare plasma homocysteine levels between patients with dry eye disease and normal control subjects.
Methods: Plasma homocysteine (enzyme immunoassay), vitamin B12, and folate levels were determined in 38 patients with dry eye and in 38 controls.
Results: Characteristics of the dry eye and control groups were similar. The mean plasma homocysteine level was 16.38 ± 6.98 μmol/L in the dry eye group and 14.39 ± 5.11 μmol/L in the control group (P = 0.10, t test). Hyperhomocysteinemia was present in the 43.9% of the dry eye patients and 33.3% of the controls (P = 0.43, χ test). There were no statistical differences between dry eye and control groups regarding plasma vitamin B12 and folate levels (P = 0.72 and P = 0.69, respectively, t test).
Conclusions: Plasma homocysteine levels in dry eye patients may be inadequate to give homocysteine a role in pathogenesis. However, in ocular diseases like glaucoma, plasma homocysteine levels are significantly higher, and associated dry eye disease may cause an additional increase in plasma homocysteine levels.