Level of disagreement between Proview phosphene tonometer and Goldmann applanation tonometer intraocular pressure readings

PURPOSE: To evaluate the agreement of intraocular pressure (IOP) readings obtained with the Proview phosphene tonometer and those obtained by Goldmann applanation tonometry as well as the effect of regular use of the Proview on patients' anxiety about their glaucoma. METHODS: One hundred thirty-five consecutive patients with glaucoma, 35 designated as controls, were enrolled in a 10-month randomized prospective clinical trial. The study patients but not the controls used the Proview outside the office. At office visits IOP was measured by an ophthalmologist with the Goldmann applanation tonometer (GAT) as well as by examiners and patients using the Proview. Patients in the treatment group (n = 100) were asked to measure and record their IOP at home as well. Using ANOVA, we examined the relationship between demographic variables and the level of agreement between the Proview readings and those measured by GAT at the final office visit. All participants also were asked to complete a questionnaire regarding their anxiety about their IOP at the baseline and final office visits. The primary outcome measure was the level of agreement of the Proview measurements with those obtained by GAT. Secondary outcome measures included patients' anxiety about their glaucoma. RESULTS: The absolute mean difference between GAT and Proview readings at the final visit was 3.5 +/- 2.9 mm Hg (median, 2.8 mm Hg). The treatment group reported significantly less anxiety about their glaucoma after 4 to 6 weeks of using the Proview (P = .024). CONCLUSIONS: There was considerable discrepancy between Proview and GAT readings. However, regular use of the Proview tonometer significantly reduced patients' anxiety about their glaucoma.