Abstract
Purpose :
Primary open angle glaucoma (POAG) patients often show an increased central retinal venous pressure (CRVP) which leads to a significantly reduced ocular perfusion pressure (OPP). Aim of the present study was to evaluate whether an increased CRVP in POAG patients is lowered by the oral administration of nitrates.
Methods :
22 eyes of 14 primary open angle glaucoma patients (11 female, 3 male, mean age 65.4±10.5 years) with an initially increased CRVP were included in the study. All patients received 50mg Pentaerithrityltetranitrat orally once daily. Topical therapy was not changed during follow up. Intraocular pressure (IOP), mean blood pressure (MAP) and CRVP were measured before treatment and after 4 months of therapy. CRVP was measured with a contact lens dynamometer calibrated in mm Hg (Imedos, Jena, Germany). For statistical analysis, the data from both eyes were combined using the mixed-model method, which adjusts for the correlation between the 2 eyes in a single person.
Results :
Intraocular pressure did not change (11.88±0.65 vs 12.02±0.59 mmHg; p = 0.77) nor did mean arterial blood pressure (89.91±7.7 vs 104.143.75 mmHg; p = 0.127). CRVP, however, showed a statistically significant decrease after 4 months of treatment (47.95±4.27 vs 28.08±2.08 mmHg; p< 0.001). No effect of treatment was found on OPP (51.33±4.64 vs 56.07±2.19 mmHg, p= 0.270), when using the wide spread formula OPP= 2/3 MAP – IOP. Inserting CRVP into the formula (OPP = 2/3 MAP – CRVPP), however, leads to a statistically significant increase in OPP (1.41±6.01 vs 39.31±2.87 mmHg, p <0,001).
Conclusions :
Orally administered nitrates (Pentaerithrityltetranitrat ) reduce an initially increased CRVP in POAG patients and therefore lead to an increase in OPP. Reduced OPP, however, represent a risk factor for the prevalence and progression of POAG. Therefore a treatment with nitrates might be beneficial for the course of the disease in patients who show an initially increased CRVP.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.