Abstract
Abstract: :
Background: Although intraocular pressure (IOP) rises when the body position is changed from sitting to supine, it is difficult to estimate the elevation of IOP of each case, which varies from 5 to 50%. Since in some cases of glaucoma, a nocturnal peak of the IOP is observed, the IOP during sleep may be unexpectedly elevated and influence on the visual field progression in glaucoma. Purpose: To investigate the factors which likely influence on the IOP rise in the supine position. Participants:328 eyes of 164 Japanese cases with various diseases. Setting:Osaka Minami Medical Center, Osaka, Japan. Methods: In all cases, IOP and ocular pulse amplitude measurement in both the sitting and the supine position is carried out using a pneumatic tonometer. The rise of IOP with the postural change was investigated with a multiple regression analysis. Results: All cases showed the IOP elevation with the postural change from the sitting to the supine position. The average IOP was 14.2 +/– 3.5 mmHg and 18.8 +/– 3.4 mmHg in the sitting and the supine position, respectively. The average elevation of IOP with the postural change was 4.7 +/– 1.5 mmHg. A multiple regression analysis showed that high amplitude of ocular pulse (p=0.002), the spherical equivalent refractive error (p=0.01) and the presence of normal tension glaucoma (p=0.001) and diabetic retinopathy (p=0.0005) were positive factors to elevate supine IOP, whereas the value of the sitting IOP was a negative factor (p=0.0000007). However, the age of patients (p=0.47), the presence of primary open angle glaucoma (p=0.54), ocular hypertension (p=0.95), systemic arterial occlusive disease (p=0.41), diabetes mellitus without retinopathy (p=0.17) and retinal vein occlusion (p=0.85) less influence on the rise of IOP with the body position change. Conclusions: A case of normal tension glaucoma with lower sitting IOP and diabetic retinopathy especially with hyperopia may have unexpectedly high elevation of IOP when lying.
Keywords: intraocular pressure