Reproducibility of the Intraocular Pressure Measurements Using Goldmann Applanation Tonometer, Dynamic Contour Tonometer and Ocular Response Analyzer

Abstract

Purpose: : To evaluate and compare the reproducibility of the intraocular pressure (IOP) measurements obtained by Goldmann Applanation Tonometry (GAT), Dynamic Contour Tonometry (DCT), and Ocular Response Analyzer (ORA).

Methods: : A prospective study was carried out. Glaucoma patients under control with medications and without ocular surgery or corneal disease that could influence the IOP measurements were enrolled. Two examiners performed the IOP measurements using GAT, DCT (Pascal) and ORA in three different sessions with an interval of one week between sessions. In each session, each examiner took two GAT, two DCT, and four ORA IOP measurements of both eyes of the patients in a random sequence. The variance components of each type of tonometry were calculated.

Results: : A total of 20 glaucoma patients (40 eyes) were included. For GAT, the intrasession-intraobserver variance was 6.27 mmHg², intersession variance was 0.06 mmHg², and interobserver variance was 0.36 mmHg². For DCT, the intrasession-intraobserver variance was 1.75 mmHg², intersession variance was 0.02 mmHg², and interobserver variance was 0.08 mmHg². For the Goldmann-correlated ORA IOP, the intrasession-intraobserver variance was 5.06 mmHg², intersession variance was 0.18 mmHg², and interobserver variance was 0.00 mmHg². For the corneal-compensated ORA IOP, the intrasession-intraobserver variance was 7.91 mmHg², intersession variance was 0.16 mmHg², and interobserver variance was 0.07 mmHg².

Conclusions: : The reproducibility of IOP measurements varied significantly between the tonometers. The DCT showed the lowest variance components, and, therefore, provided more reproducible IOP measurements.

Keywords: intraocular pressure