ABSTRACT
BACKGROUND: The authors aimed at investigating ophthalmological changes at high altitude and correlating this with blood oxidation/antioxidation parameters. METHODS: There were 40 volunteers who participated in the study. Initial ophthalmological examinations were performed at 3543 ft (1080 m) and repeated on the following day after the participants climbed to an altitude of 9186 ft (2800 m) on Mt. Erciyes, Turkey. Venous blood samples were taken at both altitudes to evaluate total oxidative system (TOS) and antioxidative system (TAS) levels. RESULTS: IOP-right eyes at 3543 ft (1080 m) was 13.23 +/- 0.43 mmHg and significantly increased to 14.45 +/- 0.56 mmHg at 9186 ft (2800 m). LOP-left eyes at 3543 ft (1080 m) was 13.50 +/- 0.44 mmHg and increased to 14.13 +/- 0.54 mmHg at 9186 ft (2800 m) (P = n.s.). Central corneal thickness (CCT) of the right eyes was 540.98 +/- 4.34 microm at 3543 ft (1080 m) and significantly increased to 549.73 +/- 4.59 microm at 9186 ft (2800 m). CCT of the left eyes was 542.13 +/- 29.01 microm at 3543 ft (1080 m) and significantly increased to 547.23 +/- 4.59 microm at 9186 ft (2800 m). Spherical equivalent refraction of right or left eyes did not show any significant changes. TOS at 3543 ft (1080 m) was 5.33 +/- 0.76 micromol H2O2 equiv/L and significantly increased to 7.55 +/- 0.82 micromol H2O2 equiv/L at 9186 ft (2800 m). TAS at 3543 ft (1080 m) was 2.45 +/- 0.12 micromol H2O2 equiv/L and decreased to 2.22 +/- 0.08 micromol H2O2 equiv/L (P = n.s.) at 9186 ft (2800 m). There was a positive correlation between TAS and LOP at 9186 ft (2800 m). CONCLUSION: Increased CCT can be related to stromal edema caused by hypoxia's effect on corneal endothelial function. Although TOS increased at high altitude, TAS did not show any parallel increase. Since this was nonacclimatized climbing, the antioxidant system could not have reached sufficient levels to counterbalance the observed oxidant stress.