Abstract
Purpose: :
To determine the relation between postural change in intraocular pressure (IOP) and severity of visual field loss in patients with primary open angle glaucoma.
Methods: :
Twenty normal patients with no evidence of glaucoma and twenty patients with primary open angle glaucoma (POAG) were studied. The intraocular pressures were measured in both eyes, first in the sitting up and then in the supine positions, using the Perkins tonometer, and compared. Visual fields were obtained with the Humphrey automated perimeter, and severity of visual field loss was determined based on the extent of total and pattern deviations.
Results: :
The mean IOP change from the sitting up to the supine position in non–glaucomatous eyes increased by 3.1 +/– 0.5 mmHg (mean +/– SEM), where in the glaucoma patients the IOP increased by 4.3 +/– 0.9 mmHg (p=0.02) in eyes with worse visual field loss, and by 3.6 +/– 0.6 mmHg in the better eyes.
Conclusions: :
A greater rise in intraocular pressure in eyes of patients with open angle glaucoma with worse visual field loss from the sitting up to the supine position, versus eyes with lesser visual field change, may explain the greater visual field loss in those eyes.
Keywords: intraocular pressure • circadian rhythms