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Abstract #13538 Published in IGR 8-1
Ex vivo evaluation of Tono-Pen and pneumotonometry in cat eyes
Stoiber J; Fernandez V; Lamar PD; Hitzl W; Fantes F; Parel JMOphthalmic Research 2006; 38: 13-18
PURPOSE: To evaluate the validity and intraobserver reliability of intraocular pressure (IOP) measurements with both pneumotonometry and the Tono-Pen in a closed ex vivo system in cat eyes. METHODS: IOP was increased step by step in 5 enucleated cat eyes, while taking IOP measurements with the Tono-Pen and pneumotonometry. The outcomes were compared to readings of a digital manometer simultaneously measuring the actual pressure in the anterior chamber. RESULTS: Pneumotonometry overestimated IOP below 15 mmHg and underestimated pressures above 20 mmHg. Tono-Pen tonometry considerably underestimated IOP over the whole spectrum in all of the eyes tested. The pneumotonometer was identified as the more valid and reliable instrument for cat eyes. CONCLUSION: Both tonometers are clinically useful tools to assess IOP for glaucoma studies using a cat animal model. However, one has to consider underestimation of IOP in the upper ranges. A correction formula can be used to calculate the actual IOP.
Dr. J. Stoiber, Bascom Palmer Eye Institute, University of Miami School of Medicine, FL 33136, USA
Classification:
6.1 Intraocular pressure measurement; factors affecting IOP (Part of: 6 Clinical examination methods)
5 Experimental glaucoma; animal models
