The Effect of Posture on Intraocular Pressure and Systemic Hemodynamic Parameters in Treated and Untreated Patients with Primary Open-Angle Glaucoma

Purpose: To assess intraocular pressure (IOP), systolic, diastolic, and mean arterial blood pressure (SBP, DBP, MAP) changes in the sitting, supine, and 20° head-down (Trendelenburg) position in treated (tPOAG) and untreated (uPOAG) primary open-angle glaucoma patients and healthy controls. Methods: All participants underwent IOP and systemic BP measurements in the sitting, supine, and Trendelenburg positions during office hours. IOP and BP readings in the sitting, supine, and Trendelenburg positions were analyzed. Results: Twenty-one tPOAG patients, 17 uPOAG patients, and 21 controls were enrolled in the study. Compared to controls, eyes in the tPOAG and uPOAG groups had significantly larger posture-induced IOP elevation upon changing from the sitting to the supine position (P = 0.020 and P = 0.032, respectively). Compared to controls, the IOP elevation in the Trendelenburg position was statistically higher for the tPOAG (P = 0.003), but not the uPOAG group (P = 0.840). All 3 groups had a similar pattern of SBP, DBP, and MAP changes. Conclusions: Compared to controls, posture-induced IOP changes are more pronounced in treated and untreated POAG patients.