Agreement of Serial iCare HOME2 and Goldmann Applanation Tonometry.

PURPOSE

To assess agreement of iCare HOME2 and Goldmann applanation tonometry over a wide range of intraocular pressure (IOP).

DESIGN

A prospective, observational cohort study.

SUBJECTS

Twenty-six adult patients undergoing intravitreal injection, which temporarily raises IOP, were recruited from the Palo Alto Medical Foundation Retina Clinic between October 2022 and February 2023.

METHODS

Subjects had serial iCare HOME2 (IOP) and Goldmann applanation (IOP) IOP measurements before and at 0 and 5 to 10 minutes after injection. Baseline IOPs and pachymetry were taken in both eyes.

MAIN OUTCOME MEASURES

Correlation between IOPand IOPwas tested by within-subjects intraclass correlation coefficient (ICC) for repeated measures. Agreement between IOPand IOPwas evaluated by a Bland-Altman plot with correction for multiple measurements. The difference between IOPand IOPwas evaluated between eyes at baseline (Pearson's r) and within the injected eye over different timepoints (ICC for absolute agreement). Linear regression was used to evaluate the effects of age, sex, glaucoma, and corneal thickness.

RESULTS

The mean IOPand IOPwere 25.3 (range: 9-55) and 23.5 (range: 8-56) mmHg, respectively. The correlation between IOPand IOPwas 0.99 (P < 0.001). The mean difference (IOP - IOP) was 2.2 mmHg (95% limits of agreement: -3.4 to 7.8 mmHg). The bias in measurements was correlated between eyes (r, 0.68; P < 0.001) and in the injected eye across all timepoints (ICC, 0.86; 95% CI, 0.75-0.93), but did not show a relationship with age, sex, glaucoma, or corneal thickness.

CONCLUSIONS

IOPand IOPshowed excellent correlation; however, there was a stable bias toward IOPbeing higher than IOPover a large range of IOP. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.