Clinical Evidence of Limited Effectiveness of a Phosphene Method for Ocular Pressure Measurement

Abstract

Abstract: : Purpose: To evaluate the "Proview^TM Eye Pressure Monitor" (Proview^TM)for reproducibility and for enabling a patient to obtain a meaningfulmeasure of one’s intraocular pressure (IOP).Methods:Prospective clinical trial. After a training session 137 subjects(healthy volunteers and glaucoma patients) obtained from oneeye five IOP measurements with each of five different Proview^TMdevices. A clinician measured the IOP using Goldmann applanation.Results: Measurements with the Proview^TM were reproducible.Within subject & within device variance, and within subject& between device variance, were low (Table 1). However,the correlation with Goldmann was not good (correlation coefficientof r = 0.41) and the scatter was large. Agreement between Proview^TMand Goldmann was particularly poor for higher Goldmann IOP (Figure1).Conclusion: The Proview^TM technique was reproducible. However,it appears to have important limitations as an indicator ofIOP as the agreement with Goldmann applanation was poor forsome individuals. The method of phosphene tonometry merits furtherstudy because it is easy to use and could allow a patient toperform frequent measurement of IOP, but our data suggest theProview^TM has limited effectiveness in its current form. 

Table 1: Components of Variance of the Proview^TM pressures 

Keywords: intraocular pressure • clinical (human) or epidemiologic studies: sys