Have You Tested Your Goldmann Tonometer Today?

Intraocular pressure (IOP) is the only known modifiable risk factor for glaucoma. Besides being a cornerstone in glaucoma management, accurate measurement of IOP forms an important component of routine ophthalmic evaluation. Despite the innovation of various newer tonometers, Goldmann applanation tonometer is still considered the Gold standard for IOP measurement. However, there are several reported sources of error including calibration error.1 Errors in calibration of Goldmann applanation tonometer are often overlooked in clinical practice. Kumar and Jivan2 conducted a questionnaire survey of 100 ophthalmology residents from UK. 85% of respondents to their questionnaire never checked tonometers for errors.2 Wessels and Oh3 did a field survey of 94 ophthalmologists’ offices to assess the accuracy of tonometers in daily use. Less than 15% of ophthalmologists in their study knew how to perform calibration error testing.3 Given the importance of applanation tonometry in glaucoma management and the ease of calibration error testing, these figures are surprising.