Posture-induced intraocular pressure changes in eyes with open-angle glaucoma, primary angle closure with or without glaucoma medications, and control eyes.

Purpose: To compare the posture-induced intraocular pressure (IOP) changes in eyes with open-angle glaucoma (OAG), primary angle closure (PAC) with or without glaucoma medications, and healthy control eyes with normal IOPs.
Methods: The IOP was measured in the sitting position (SP) and the lateral decubitus position (LDP) with a rebound tonometer. The IOP in the LDP was measured in the upper eyes 5 minutes after assuming this posture.
Results: Fifty-two patients with OAG, 52 with PAC, and 52 controls with normal IOPs were studied. The IOP in the SP measured with the rebound tonometer was 14.3 ± 4.0 mm Hg in eyes with OAG, 15.8 ± 4.5 mm Hg in eyes with PAC, and 13.9 ± 3.7 mm Hg in eyes with normal IOPs. None of these differences was significant (P = 0.060; ANOVA). The IOP in the LDP was significantly increased to 18.3 ± 4.6 mm Hg in eyes with OAG, 19.3 ± 4.4 mm Hg in eyes with PAC, and 17.3 ± 3.5 mm Hg in eyes with normal IOPs (P = 0.000 for all; paired t-tests). The postural IOP difference was +4.0 ± 2.2 mm Hg in OAG eyes, +3.5 ± 2.2 mm Hg in PAC eyes, and +3.4 ± 1.8 mm Hg in normal eyes, and these increases were not significantly different among the three groups (P = 0.309; ANOVA). The correlation between the posture-induced IOP changes and the axial length was not significant in each group.
Conclusions: Postural IOP changes are comparable among eyes with OAG, PAC with and without glaucoma medications, and control eyes.