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.
Comparison between provocative test-based and long-term intraocular pressure parameters in patients with stable open-angle glaucoma
Purpose: To compare provocative test-based and long-term intraocular pressure variation parameters in patients with stable open-angle glaucoma. Methods: A prospective observational study was carried out in which stable open-angle glaucoma patients (⩾3 years of follow-up without any changes on current medical regimen) were consecutively enrolled. All patients were submitted to a water-drinking test. Long-term intraocular pressure parameters were obtained from isolated intraocular pressure measurements from each visit (⩾5 visits). We investigated the correlation and agreement between the following water-drinking test and long-term intraocular pressure parameters: mean, peak, and fluctuation. In addition, the percentage of eyes with significant intraocular pressure peaks during the water-drinking test (defined as a difference ⩾25% between water-drinking test intraocular pressure peak and mean long-term intraocular pressure) was assessed. Results: Sixty-three eyes from 63 open-angle glaucoma patients (mean age, 60.7 ± 11.8 years) were included. Mean and water-drinking test intraocular pressure peak correlated significantly with mean ( r = 0.67) and maximum long-term intraocular pressure ( r = 0.52), respectively ( p < 0.01). The correlation between water-drinking test intraocular pressure fluctuation and long-term intraocular pressure fluctuation was not significant ( p = 0.45). Limits of agreement from Bland–Altman plots exceeded the maximum allowed difference between methods (3 mm Hg) for all the intraocular pressure parameters analyzed, suggesting poor agreement between water-drinking test–derived and long-term intraocular pressure values. Overall, significant water-drinking test intraocular pressure peaks were observed in 39.7% of these eyes with stable open-angle glaucoma. Conclusion: Although some water-drinking test–based and long-term intraocular pressure parameters correlate significantly, water-drinking test results may not reflect the long-term intraocular pressure profile of stable open-angle glaucoma patients, as their agreement is poor. Many of these patients may experience significant water-drinking test intraocular pressure peaks, despite long-standing stable disease and unchanged medical regimen.