Mason, OH—Researchers at the Veterans Affairs Boston Healthcare System found that Haag-Streit’s single use Tonosafe disposable tonometer prisms are a reliable alternative to the Goldmann Applanation Tonometer (GAT). The study was published online by Eye: The Scientific Journal of the Royal College of Ophthalmologists (see: http://www.nature.com/eye/journal/v25/n5/full/eye201140a.html).

Tonosafe disposable prism covers replace the multi-use prisms created for the GAT.

The study is the largest to date, measuring the intraocular pressure of 652 eyes (326 patients) with Tonosafe and with the GAT. Previous studies comparing Tonosafe with the GAT primarily included patients within the normal range. This investigation also included patients at the extremes of intraocular pressure measurements, within the range of 3-34 mm Hg.

Linear regression analysis showed R=0.93 and slope=0.91, supporting the researchers’ proposed hypothesis. The y-intercept=-1.05 was significantly different than the hypothesized value.

Tonosafe test-retest repeatability (40 eyes of 40 patients) was very high with r=0.977. That was further supported by linear regression slope=0.993, y-intercept=0.118.

The Tonosafe repeatability coefficient was 2.06—similar to GAT repeatability.

About Haag-Streit

Headquartered in Bern, Switzerland, with its U.S. headquarters in Mason, Ohio, Haag-Streit manufactures optical instruments for ophthalmologists and optometrists. The company has a 150-year history, and for more than a half a century, the Haag-Streit slit lamp has been regarded as the standard instrument for ophthalmic diagnosis. For more information, visit www.haag-streit-usa.com.

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 NOTE TO EDITORS: Photos available. Contact Liz Vogel at 513-947-1444, ext. 18 or lizv@ideopia.com.