Comparison of Intraocular Pressure Measurements Using iCare Rebound Tonometry and Goldmann Applanation Tonometry: A Systematic Review and Meta-Analysis

Precis: This systematic review and meta-analysis found iCare rebound tonometry had significantly lower IOP readings compared to GAT across adult populations, with high heterogeneity and low certainty of evidence precluding definitive conclusions regarding iCare and GAT agreement Purpose: This systematic review and meta-analysis aimed to comprehensively evaluate the concordance between iCare tonometry and Goldmann applanation tonometry (GAT) for intraocular pressure (IOP) measurement in adult patients commonly encountered in routine clinical practice. Methods: Ovid MEDLINE, Embase, Web of Science, Scopus, and CENTRAL were searched from January 2015 to October 2025. Included studies quantitatively compared in-clinic iCare tonometry with GAT in adults (mean differences, limits of agreement, or intra-class correlation coefficient). Three-level random-effects meta-analysis pooled mean difference in IOP measurements for iCare minus GAT. Risk of bias was evaluated using the Quality Assessment for Diagnostic Accuracy Studies 2 checklist. Results: Thirty-three studies were included in the systematic review, and 31 studies in the meta-analysis. The pooled mean difference for iCare minus GAT IOP measurement in 5,593 eyes was -0.51 mmHg (95% CI -0.96 to -0.06 mmHg, I 2 =97.65%, P =0.03). Subgroup analysis demonstrated insignificant pooled mean differences (QM(3)=0.26, P =0.86) across the different iCare models, with values of -0.96 mmHg for IC100, -0.64 mmHg for IC200, -0.39 mmHg for TA01i, and -0.36 mmHg for the iCare Pro. Most studies had low or unclear risk of bias and applicability concerns. Conclusions: iCare tonometry had lower readings than GAT on average, but high heterogeneity and wide limits of agreement suggest that measurements are not directly interchangeable across clinical settings or individual patients.