Abstract
Purpose: :
Oxidative stress plays a major role in the pathogenesis of glaucoma by either affecting trabecular meshwork with elevation of intraocular pressure or inducing degeneration of the optic nerve and the retinal ganglion cells. Glutathione is a major antioxidant molecule existent in intracellular or extracellular space. A decrease in circulating glutathione level was reported in primary open angle glaucoma. Herein we aimed to know circulating glutathione level in normal tension glaucoma (NTG) which compromises the largest proportion of glaucoma in Korean population.
Methods: :
Case control study. 24 NTG patients (NTG group) and 30 age-gender-matched normal control subjects (control group) were included. Antecubital venous puncture was done to obtain 3ml venous blood sample at 8 to 10 o’clock in the morning. Total glutathione level was measured by spectrophotometric method at 412 nm. Correlation with mean deviation and pattern standard deviation of Humphrey visual field test was analyzed in NTG group.
Results: :
Total glutathione level in circulating blood was 524.02 ± 231.09 nmol and 586.06 ± 156.08 nmol in NTG group and in control group respectively. Difference of these values was statistically not significant (p=0.267). Age had no significant effect on the total glutathione level in both NTG group (P=0.171, r=-0.328) and control group (P=0.380, r=-0.166). In NTG group, circulating total glutathione level had no significant relationship with MD (P=0.226, F=1.636) and PSD (P=0.200, F=1.766) after correcting age and gender influence.
Conclusions: :
Oxidative stress may do harm rather to aqueous outflow pathway than to optic nerve and the retinal ganglion cells. In NTG patients, circulating total glutathione levels were not decreased comparing to that of normal subjects.
Keywords: antioxidants • optic nerve • intraocular pressure