Photo Credit: Zorica Nastasic

The following is a summary of “Increased aqueous humor levels of endothelin-1 in patients with open angle glaucoma,” published in the January 2025 issue of Ophthalmology by Hedberg-Buenz et al. 

Endothelin-1 (ET-1), a strong vasoconstrictor, plays a role in regulating vascular perfusion, with abnormal levels observed in aqueous humor in various eye vascular diseases, including glaucoma.  

Researchers conducted a retrospective study to analyze aqueous humor for ET-1 levels in patients undergoing ocular surgery and examine its association with glaucoma.  

They enrolled 62 patients with an open angle glaucoma (n=62 total) from the University of Iowa Hospitals and Clinics, divided into 4 groups: primary open angle glaucoma (POAG, n=25), normal tension glaucoma (NTG, n=17), exfoliation glaucoma (XFG, n=8), and normal controls (n=12). Aqueous humor samples were collected during glaucoma surgeries (minimally invasive glaucoma surgeries, trabeculectomy, glaucoma drainage device implantation) for the glaucoma groups and cataract extraction for the control group, ELISA was used to measure ET-1 levels, which were compared across groups and linear regression was applied to control for age and sex covariates.  

The results showed that ET-1 levels were higher in the POAG (mean ± SD: 7.8 ± 5.1 pg/mL; P = 0.002) and NTG (6.1 ± 3.0 pg/mL; P = 0.030) cohorts compared to controls (4.0 ± 1.9 pg/mL). No significant difference was found in the XFG cohort (6.2 ± 4.5 pg/mL; P = 0.230) vs controls. A combined glaucoma cohort (POAG, NTG, XFG) had significantly elevated ET-1 compared to controls (P = 0.021). Age and sex did not significantly affect ET-1 levels (P = 0.60 and P = 0.27). Adjusting for age and sex minimally influenced the comparison of POAG with controls (P = 0.018) and had a nominal impact on NTG (P = 0.089) and XFG (P = 0.15) comparisons.  

Investigators concluded the patients with POAG and NTG exhibited higher levels of -ET-1 compared to healthy controls, while levels in patients with XFG were not significantly different. This elevation in ET-1 was observed in the combined glaucoma cohort and remained significant after adjusting for age and sex. 

Source: bmcophthalmol.biomedcentral.com/articles/10.1186/s12886-025-03861-y