P9.5 Vascular Structure and Function and Hemodynamics are not Altered in Normal-Tension Glaucoma at Rest

Aims In normal-tension glaucoma (NTG), optic nerve damage occurs despite a normal intraocular pressure. Studies implicating arterial stiffness in the pathophysiology of NTG have produced conflicting results. Our aim was to investigate whether NTG is associated with alterations in arterial structure or function. Methods Cardiovascular measurements included peripheral and central (Sphygmocor) blood pressures, measures of wave reflection (reflection magnitude and augmentation index), segmental and local arterial stiffness measures [carotid-femoral Pulse wave velocity (cf-PWV, Sphygmocor) and carotid artery stiffness (Esaote AU5 Wall track system), respectively], Intima-media thickness (IMT), cardiac output (Esaote AU5) and total peripheral resistance index (TPRI). Symptoms of vascular dysregulation were assessed using a questionnaire. Results 30 patients with NTG (mean age 65y, range 46–79) and 33 healthy subjects (mean age 67y, range 42–79) matched for age and sex were recruited. There were no statistically significant differences in cardiovascular measures; for NTG versus controls, respectively: blood pressure 126±15 / 77±8 mmHg vs. 127±16 / 76±7 mmHg, p=0.81; cf-PWV 9.8±2.1 m/s vs. 10.1 ±1.9 m/s, p=0.60; TPRI 1833±609 vs. 1779±602 dyne.s/cm5/m 2 , p=0.79; carotid IMT 0.65±0.14 mm vs. 0.68±0.13 mm; p=0.39. Questionnaire reports revealed an increased prevalence of cold extremities in the NTG group (73% vs. 21%, p<0.001) suggesting vascular dysregulation is present in most NTG patients. Conclusion NTG is not associated with altered arterial stiffness, IMT, TPRI, cardiac output, peripheral or central hemodynamics. Although the majority of NTG patients exhibit symptoms of vascular dysregulation, in the present study this did not translate into alterations in the micro- or macrocirculation at rest.