Levels of Plasma 8-Hydroxy-2'-Deoxyguanosine—A Marker of Oxidative DNA Damage—Are Not Associated with Primary Angle-closure Glaucoma

Abstract

Aim: The study aimed to estimate plasma 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, a marker of oxidative deoxyribonucleic acid (DNA) damage, and evaluate their potential association with primary angle-closure glaucoma (PACG) and related clinical markers. Study Design: This is retrospective case-control study. Place and Duration: The study was performed on samples recruited from King Abdulaziz University Hospital, Riyadh, Saudi Arabia between August 2018 through September 2019 in the participants of Saudi origin. Methodology: Plasma 8-OHdG levels were measured in duplicates using automated ELISA analyzer in 43 PACG patients and 45 non-glaucomatous controls. Results: The mean levels of 8-OHdG were 13.59 ng/mL [±4.50] in PACG patients compared to 16.95 ng/mL [±10.66] in controls. The differences did not achieve statistical significance (P = 0.06). Similarly, no significant differences (P = 0.42) were observed in the median levels of 8-OHdG between PACG and controls. Furthermore, except for sex, where males exhibited a significant negative correlation (R = -0.35, P = 0.02), there was no significant correlation between 8-OHdG levels and age (P = 0.85), intraocular pressure (P = 0.58), cup/disc ratio (P = 0.39) and number of antiglaucoma medications (P = 0.41) in the PACG group. Regression analysis showed no significant influence of age, sex, and 8-OHdG levels on PACG outcome. Besides, the area under the receiver operating characteristic curve was 0.55 and non-significant (P = 0.42). Conclusion: There is no association between plasma levels of 8-OHdG and PACG or its specific clinical markers. Further studies in a much larger cohort are needed to validate these findings.