J Korean Ophthalmol Soc.  2021 May;62(5):665-673. 10.3341/jkos.2021.62.5.665.

Usefulness of the Icare ic200 Rebound Tonometer in Korean

• Lee Ju
• Park KS
• Kim J
• Lee SB
• Lee YH
• Kim KN

• KMID: 2515949
• DOI: http://doi.org/10.3341/jkos.2021.62.5.665

Abstract

Purpose
To evaluate the efficacy of the Icare ic200 in clinical practice by comparing the intraocular pressure (IOP) measured with the Icare ic200 rebound tonometer to the IOP measured with the Goldmann applanation tonometer (GAT).
Methods
A total of 294 eyes of 294 Korean patients were included. IOP was measured with the Icare ic200 and then measured again with a GAT in all patients. We evaluated the degree of IOP agreement between the two tonometers and analyzed the diagnostic ability of the Icare ic200 for a reading ≥ 22 mmHg with the GAT. We also analyzed whether clinical factors including biometry affected the difference in IOP measured by the two tonometers.
Results
The IOP values measured with the Icare ic200 and GAT were strongly correlated (r = 0.875, p < 0.001). The IOP measured with the Icare ic200 was lower than the IOP measured with GAT. The mean difference was 3.07 ± 2.67 mmHg, and 95.24% of patients were distributed within the 95% limits of agreement (-2.16 to 8.30 mmHg) on Bland-Altman plots. The diagnostic ability of the Icare ic200 for IOP ≥ 22 mmHg was 0.959 (area under the receiver operating characterisitic). In multivariate regression analyses, older age (β = 0.034, p = 0.020) and greater corneal curvature (β = 0.213, p = 0.030) were correlated with larger IOP differences between the two tonometers.
Conclusions
Although the Icare ic200 was more consistent than the GAT with reasonable diagnostic ability for ≥ 22 mmHg, the IOP measured 3 mmHg lower than the GAT. Therefore, the Icare ic200 might be more useful as a screening test to increase IOP rather than replacing GAT in clinical practice.

Keyword

Glaucoma, Goldmann applanation tonometer, Icare ic200, Rebound tonometer