Vascular Parameters and Endothelin 1 Measurements in Glaucoma Patients With Low and High-tension Optic Disc Hemorrhages

Abstract

Purpose: To compare vascular parameters, assessed by endothelin-1 (ET-1) blood levels, Laser Doppler Imaging (LDI) of distal phalanx, and nailfold capillaroscopy (NC), between open-angle glaucoma (OAG) patients with low (LTDH) and high-tension optic disc hemorrhages (HTDH). Methods: In this prospective study, patients were classified as LTDH if presenting an IOP<16 mmHg and HTDH if an IOP³16 mmHg at the time of DH detection. Demographic and ophthalmological data, ET-1 concentration, LDI (before and after 1, 10 and 20 minutes after cold stimulation) and NC findings were evaluated. Results: Thirty-tree patients were included (mean age, 62.3±13 years). Regarding ET-1 blood level, it was 65% higher in the LTDH group (2.27±1.46 pg/ml) compared to the HTDH (1.37±0.57 pg/ml; p=0.03). In addition, there was a significant negative correlation between ET-1 blood concentration and IOP at the time of DH detection (r=-0.45; p=0.02). Blood flow measurement in LTDH patients were lower than those observed in patients with HTDH 10 and 20 minutes after cold stimulus (p<0.01). Conclusion: Patients developing DH with lower IOPs have higher ET-1 blood levels and more peripheral vascular dysfunction (than those with higher IOPs), as estimated by LDI. These findings suggest that distinct underling mechanisms maybe involved in patients developing DH with different IOP ranges.