Clinical Comparison of the ProviewTM Eye Pressure Monitor with Goldmann Applanation Tonometer and Tono-Pen

Abstract

Abstract: : Purpose: To compare the IOP values obtained by patients using the Proview^TM eye pressure monitor with those measured with Goldmann tonometer and the Tono-Pen. Methods: Eighty-six patients (171 eyes) with a diagnosis of glaucoma or glaucoma suspect successfully completed the study. IOP was measured by three methods in the following order: Goldmann tonometer, Tono-Pen, and the Proview^TM. Two readings were made for each method and then averaged. The central corneal thickness (CCT) was measured by an ultrasonic pachymeter. The ease of using the Proview^TM and the discomfort associated with its use were assessed. Separately for each eye, the differences in mean IOP values between measurement methods were assessed using paired t-tests and also in multivariate models that tested the dependency of IOP difference on CCT with the Wilkes’ lambda test. Pearson correlation coefficients between the IOP values obtained with Goldmann and Proview^TM and Goldmann and Tono-Pen were calculated. An analysis of variance (ANOVA) was used to determine whether there was a difference among categories of ease for the difference between the IOPs measured by Goldmann and the Proview^TM. Results: No discomfort was associated with the use of the Proview^TM eye pressure monitor. Eighty one percent of patients described using the Proview^TM as "easy or very easy". For the right eye, the mean IOPs were 17.2 mmHg, 15.6 mmHg, and 13.8 mmHg by Goldmann, Tono-Pen, and Proview^TM, respectively, and for the left eye; the values were 16.2 mmHg, 14.7 mmHg, and 13.4 mmHg. There was a significant difference (p<0.001) between methods for the mean IOPs in either eye, and the difference was independent of the CCT. Pearson correlation coefficients between the IOP values obtained with Goldmann and Proview^TM were 0.50 for the right eye and 0.46 for the left eye. For Goldmann and Tono-Pen, the coefficients were 0.93 for the right eye and 0.87 for the left eye. The differences between IOP measured by Goldmann and Proview^TM were similar in all categories of patient-reported ease of using the Proview^TM. Conclusions: The IOPs obtained with the Proview^TM are significantly lower than those measured with Goldmann tonometer and the Tono-Pen, and variations of the CCT do not contribute to the difference. There is no strong correlation between the IOP values obtained with the Goldmann and the Proview^TM. On the other hand, as expected, measurements with Goldmann and Tono-Pen correlated well. The Proview^TM was not a useful tool for home IOP monitoring in this study sample of patients.

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