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Postural Change in Intraocular Pressure: A Comparison of Measurement With a Goldmann Tonometer, Tonopen XL, Pneumatonometer, and HA-2

Barkana, Yaniv MD

Journal of Glaucoma:
doi: 10.1097/IJG.0b013e3182a0762f
Online Articles: Original Studies
Abstract

Purpose: To compare directly the results of 4 tonometers in measuring postural change in the intraocular pressure (IOP) between sitting and lying body positions.

Methods: In 19 healthy subjects, the IOP was measured both eyes with a Goldmann applanation tonometer (GAT) while sitting, then using the same GAT with the subject in the left lateral decubitus position after lying for 15 minutes, using a novel system comprising a motorized bed and a modified slit-lamp table. On the next day, the sitting IOP was measured in 1 eye using GAT, and additionally in random order Tonopen XL and pneumatonometer. Then subjects were asked to lie down, and the IOP was measured with these tonometers and also with a hand-held applanation tonometer (HA-2) after lying for 15 minutes and for 45 minutes; measurements were made with subjects in the supine position except with GAT.

Results: There were 10 male and 9 female subjects, with a mean age of 33.0±12.4 years. On day 1, the sitting GAT IOP (mm Hg) was 13.7±3.0 right eye and 13.6±2.8 left eye (P=0.7) and the lying GAT IOP was 17.8±3.5 right eye and 18.1±3.2 left eye (P=0.3 for inter-eye postural IOP change). Postural change in the right and the left eyes was moderately correlated, with a coefficient of 0.453. On day 2, postural changes after lying for 15 minutes as measured with a GAT, a Tonopen, a pneumatonometer, and a HA-2 were 4.9±2.6, 1.6±1.8, 4.2±2.0, and 3.1±2.7, respectively. After lying for 45 minutes, it decreased to 3.3±2.1, 1.1±4.3, 3.1±2.5, and 2.6±3.3, respectively; this IOP decrease was statistically significant for the GAT and the pneumatonometer. The inter-subject variability was large, as in some subjects there was nearly no postural change in the IOP, whereas in some the IOP increased by 8 to 10 mm Hg. Ninety-five percent limits of agreement showed a poor agreement between GAT and the other 3 tonometers in the sitting and lying IOPs and postural IOP changes measured.

Conclusions: The average postural IOP change was similar when measured with GAT and a pneumatonometer, smaller with a hand-held GAT, and much smaller with a Tonopen XL. This change decreased significantly when lying between the 15- and 45-minute time points. The inter-subject variability in postural IOP was remarkable, consistent with previous reports, suggesting the importance of this parameter in clinical glaucoma practice. Inter-device agreement was poor and similar to previous reports.

Author Information

Department of Ophthalmology, Assaf Harofe Medical Center, Zerifin, Israel

This study was presented in part during ARVO 2013 (poster 5615).

Disclosure: Supported by Sensimed AG, Lausanne, Switzerland. The sponsor participated in the design of the study, conducting the study, data management, data analysis, and review of the manuscript.

Reprints: Yaniv Barkana, MD, Department of Ophthalmology, Assaf Harofe Medical Center, Zerifin 70300, Israel (e-mail: yanivbarkana@gmail.com).

Received January 29, 2013

Accepted June 2, 2013

© 2014 by Lippincott Williams & Wilkins.