Abstract
Abstract: :
Purpose:Aim of this study was to investigate the diurnal course ot intraocular pressure (IOP) and ocular perfusion in normal pressure glaucoma patients (NPG).(NPG). Methods: In a prospective clinical trial 46 eyes of 24 patients with NPG (mean age 69.4+/-9.3y) were examined. IOP was measured by applanation tonometry and pulsastile ocular blood flow (pOBF) by the ocular blood flow system (OBF). In addition heart rate and blood pressure were taken. With both instruments diurnal measurements were performed every 4 hours for 2 days (4am and midnight measurements in supine position). Means for IOP and pOBF and the presence of maximum diurnal IOP at each time were calculated. Statistics were performed by univariate linear regression analysis and students t-test. Results: Mean IOP was 14.42+/-2.36mmHg at 4am, 14.23+/-2.43mmHg at 8am, 14.19+/-2.77mmHg at 12pm, 14.53+/-2.85mmHg at 4pm, 14.27+/-2.53mmHg at 8pm, and 14.89+/-2.13mmHg at midnight. IOP was statistically significant higher at midnight compared to 4am (p=0.008), 8am (p=0.003), 12am (p=0.016), 4pm (p=0.118) and 8pm (p=0.004). The maximum diurnal IOP was present at 4am in 13.0% of the patients, at 8am in 13.0%, at 12pm in 8.7%, at 4pm in 19.6%, at 8pm in 4.3%, and at midnight in 41.3%. The presence of maximum diurnal IOP at midnight was statistically significant higher compared to all other times (p=0.000). Mean pOBF was 832.88+/-222.91µl/min at 4am, 888.67+/-253.18µl/min at 8am, 877.23+/-208.60µl/min at 12pm, 854.71+/-231.44µl/min at 4pm, 866.12+/-205.67µl/min at 8pm, and 839.63+/-201.16µl/min at midnight. POBF was statistically significant lower at midnight compared to 8am (p=0.003) and 8pm (p=0.049). Heart rate and blood pressure did not show any significant changes. Conclusions: NPG patients showed highest IOP and lowest ocular perfusion at midnight. As a high IOP and low ocular perfusion could lead to optic nerve damage, the evaluation of these parameters at night time seems to be important in the management of these patients
Keywords: intraocular pressure • visual fields • imaging methods (CT, FA, ICG, MRI, OCT, RTA, S