Aqueous Humor Antioxidants in Glaucoma: Correlations With Subtypes, Intraocular Pressure, and Medication Use-A Prospective Study.

Purpose: To investigate the correlations between aqueous humor total antioxidant capacity (TAC) and glaucoma subtypes, intraocular pressure (IOP), and glaucoma medications.

Methods: This was a prospective case-control study that included 303 patients who underwent cataract surgery between April 2019 and September 2024. The participants were categorized into primary open-angle glaucoma (POAG), primary angle-closure glaucoma (PACG), neovascular glaucoma (NVG), uveitic glaucoma (UG), and control groups. Aqueous humor samples were collected at the onset of surgery, and TAC and ascorbic acid (AA) levels were measured.

Results: Significant differences in TAC levels were observed among glaucoma subtypes, with UG showing the highest levels, followed by POAG, PACG, and NVG (P < 0.001). Multivariate linear regression further revealed that TAC levels were significantly associated with maximal IOP history (β = -0.013; 95% confidence intervals [CI], -0.023 to -0.002; P = 0.017) and IOP fluctuations (β = -0.016; 95% CI, -0.027 to -0.004; P = 0.007). However, no correlation was found between TAC levels and glaucoma medications; therefore, TAC may play a role in glaucoma pathophysiology and may serve as a potential therapeutic target.

Conclusions: Glaucoma subtype and IOP dynamics significantly influenced the TAC levels of aqueous humor. Future research could target antioxidant therapies for patients with low TAC, particularly those with PACG, NVG, or a history of elevated or fluctuating IOP.

Translational relevance: This study highlights the significant variation in TAC among glaucoma subtypes and its association with fluctuating IOP and thus contributes to a deeper understanding of glaucoma pathogenesis and provides information for future therapeutic research.