Outcomes of the Icare Rebound Tonometer versus the Gold Standard Tonometer in Measuring Intraocular Pressure among Mzuzu University Students, Malawi

Abstract

Introduction The Goldmann Applanation Tonometer (GAT) is accepted as the gold standard tool to measure Intraocular Pressure (IOP). Besides, there is an emerging Icare Rebound Tonometer (RBT) which can be an alternative in terms of measuring IOP. Objective This research aimed to analyze the agreement, and repeatability of intraocular pressure (IOP) measurements and compare the outcomes of RBT and GAT among Mzuzu University Students in Malawi. Methods For this cross-sectional study, 107 participants aged 18 to 29 years underwent ophthalmic examination with three IOP measurements taken by two examiners using the RBT and the GAT. Results The RBT and GAT were found to have a strong correlation (r=0.809, p>0.001), with an intra-class correlation of 0.787 (p>0.001). The mean difference of IOP measured by the two machines was 1.99±1.05mmHg, which was statistically significant. However, according to Bland-Altman analysis, there was no agreement between the results given by the two machines, with a bias of-1.979 (CI-2.28,-1.68, p > 0.001). In terms of repeatability, GAT was found to be better than RBT, with a CR of 7.512 and 10.418 respectively. Conclusion The RBT and GAT can offer comparable IOP measures. Therefore, RBT can be recommended for community outreach programs where GAT cannot be employed.