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 patientsʼ 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 patientsʼ 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 patientsʼ anxiety about their glaucoma.