Endothelin-1 plasma levels and vascular endothelial dysfunction in primary open angle glaucoma.

Area of Science:

• Ophthalmology
• Vascular Biology
• Immunology

Background:

• Primary open-angle glaucoma (POAG) is a leading cause of irreversible blindness.
• Endothelial dysfunction and inflammation are implicated in glaucoma pathogenesis.
• Endothelin 1 (ET-1) is a potent vasoconstrictor with potential roles in ocular vascular diseases.

Purpose of the Study:

• To investigate the association between endothelial dysfunction, ET-1 plasma levels, and subclinical intraocular inflammation in POAG patients.
• To determine if these markers correlate with progressive visual field damage in POAG.
• To explore the relationship between ET-1, vascular function, and inflammation in POAG.

Main Methods:

• Forty POAG patients with progressive visual field damage and controlled intraocular pressure (IOP) were compared to age- and sex-matched healthy controls.
• Ophthalmological examination, standard achromatic perimetry (SAP), and anterior chamber cellularity (FLARE) assessment were performed.
• Blood samples for ET-1 plasma levels and brachial artery flow-mediated dilation (FMD) using ultrasonography were measured.

Main Results:

• POAG patients exhibited significantly higher ET-1 plasma levels (2.83 vs. 1.75 pg/ml) and increased FLARE (9.98 vs. 5.87 photons/ms) compared to controls.
• POAG patients demonstrated significantly lower FMD values (4.46% vs. 13.18%), indicating endothelial dysfunction.
• Follow-up revealed a further increase in ET-1 and decrease in FMD in POAG patients over one year.

Conclusions:

• Elevated ET-1 levels in POAG are strongly correlated with vascular dysfunction (r=0.942, p=0.001).
• Vascular dysfunction is significantly associated with sub-clinical intraocular inflammation (r=0.968, p=0.001).
• ET-1 and vascular dysfunction, driven by sub-clinical inflammation, may be critical in the progression of visual field damage in POAG with controlled IOP.