HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (3) Citing Articles via Google Scholar Google Scholar Articles by Lim, K. S. Articles by Khaw, P. T. Search for Related Content PubMed PubMed Citation Articles by Lim, K. S. Articles by Khaw, P. T.

Accuracy of Intraocular Pressure Measurements in New Zealand White Rabbits

¹From the Glaucoma Service and ⁴Research and Development, Moorfields Eye Hospital, London, United Kingdom; the ²Ocular Repair and Regeneration Biology Unit and the ³Department of Pathology, Institute of Ophthalmology, London, United Kingdom.

PURPOSE. Rabbits are commonly used for the evaluation of drugs and surgery to lower intraocular pressure (IOP). The accuracy of intraocular pressure measurement is therefore critical in the analysis of data and subsequent extrapolation to humans. The purpose of this study was to establish the most reliable technique, from several currently available methods, of measuring IOP in New Zealand White rabbits.

METHODS. The IOPs of 11 healthy New Zealand White rabbits were measured with a fluid-filled pressure transducer system that was connected to the anterior chamber of each animal so that the IOP could be varied by altering the height of a bottle of balanced salt solution. Intraocular pressures were recorded over a range of 50 to 0 mm Hg by the transducer system, and comparative measurements at the same pressures were performed with the Tonopen XL (Mentor, Norwell, MA), the Perkins handheld applanation tonometer (Clement Clarke, Harlow, UK), and the Ocular Blood Flow (OBF) pneumatonometer (OBF Laboratories, Wiltshire, UK).

RESULTS. All three tonometers underestimated the true IOP, especially at higher pressures. Although the mean difference in actual and tonometric IOP was least in the Tonopen XL, there was a high degree of variability through the entire range of IOPs measured. The Perkins tonometer, although slightly less accurate than the Tonopen XL, was more consistent in measurement. The OBF pneumatonometer was the least-reliable estimate of IOP.

CONCLUSIONS. All tonometers underestimate IOP, with increasing inaccuracy at higher pressures. The Perkins applanation tonometer was the most reliable for measuring IOP in the range of 0 to 50 mm Hg in New Zealand White rabbits.

This article has been cited by other articles:

				C. U Onyimba, N. Vijapurapu, S J. Curnow, P. Khosla, P. M Stewart, P. I Murray, E. A Walker, and S. Rauz Characterisation of the prereceptor regulation of glucocorticoids in the anterior segment of the rabbit eye. J. Endocrinol., August 1, 2006; 190(2): 483 - 493. [Abstract] [Full Text] [PDF]