The pressure phosphene tonometer - A clinical evaluation

Abstract

Aims: Pressure phosphene tonometry is said to assess intraocular pressure by inducing a pressure phosphene. This study compared the results of this relatively new technique with Goldmann applanation tonometry. Methods: A total of 100 patients (196 readings) in a general ophthalmology clinic at Dunedin Hospital who consented to take part in this study were randomised to receive by different examiners either pressure phosphene tonometry by a Proview™ eye pressure monitor (Bausch & Lomb Inc., Tampa, FL, USA) or Goldmann tonometry first. There was no communication between the examiners regarding results. Results: Of the 196 attempted readings, pressure phosphene tonometer readings were only able to be obtained for 136 eyes (69%) compared to all 196 (100%) eyes with the Goldmann tonometer. The mean IOPs were 18.5 mmHg using the pressure phosphene tonometer and 16.0 mmHg using the Goldmann tonometer. The mean difference was + 2.43 mmHg (95% confidence interval: 10.37 mmHg below to 15.22 mmHg above Goldmann readings). Conclusion: This study found that 31% of patients could not perceive a pressure phosphene using the Proview™ eye pressure monitor. Data obtained from those who could perceive the phosphene indicated that large discrepancies between pressure phosphene tonometry and Goldmann tonometry were common. © 2005 Nature Publishing Group All rights reserved.