Agreement between iCare HOME and Goldmann applanation tonometry: systematic review and meta-analysis

This systematic review and meta-analysis evaluated agreement between the iCare HOME rebound self-tonometer and Goldmann applanation tonometry (GAT) for intraocular pressure (IOP) measurement in adults.

Ovid MEDLINE, Embase, Scopus, Web of Science, and Cochrane CENTRAL were searched from January 2015 to May 2026. Eligible studies compared in-clinic or at-home iCare HOME, including HOME and HOME2 models, with GAT in adults using mean differences, limits of agreement, or intraclass correlation coefficients. Random-effects meta-analysis pooled the mean difference in IOP for iCare HOME minus GAT. Risk of bias was assessed using QUADAS-2, and certainty of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE). Post hoc analyses addressed unit of analysis, operator, and measurement variability.

Twenty-two studies including 1857 eyes of 1517 patients were included; 16 studies involving 1333 eyes contributed to the meta-analysis. The pooled mean difference was -0.21 mm Hg (95% CI: -0.73 to 0.31; I² = 94.2%; p = 0.42). A prespecified REML Hartung-Knapp analysis was similar (95% CI: -0.82 to 0.39). The pooled standard deviation of paired differences was 2.66 mm Hg, corresponding to individual-level limits of agreement of approximately ±5 mm Hg. Leave-one-out, subgroup, and 1-eye-per-participant analyses did not materially change the results (1 eye per participant, -0.40 mm Hg; 95% CI: -1.18 to 0.38). Egger's test suggested possible small-study effects. GRADE certainty was very low because of inconsistency, imprecision, and possible publication bias.

iCare HOME showed no significant systematic bias relative to GAT, including with 1 eye per participant, but substantial heterogeneity and wide individual-level agreement limits preclude routine interchangeability.