Related Experiment Video
Updated: Jan 31, 2026

Echocardiographic Evaluation of Atrial Communications before Transcatheter Closure
Published on: February 8, 2022
Comparison of Three Different Tonometers in Eyes with Angle Closure
Tae-Eun Lee1,2, Chungkwon Yoo, Yong Yeon Kim2
1Department of Ophthalmology, Chonbuk National University Medical School and Hospital, Jeonju, South Korea.
Significance:
Precise measurement of intraocular pressure (IOP) is essential when diagnosing and managing glaucoma. We compared the IOP readings of three different tonometers and analyzed agreement among tonometers in eyes with high IOPs.
Purpose:
The purpose of this study was to compare the IOP readings obtained using a Goldmann applanation tonometer (GAT), a rebound tonometer (RT), and a Tono-Pen (TP) in angle-closure eyes with elevated IOP before and after medical IOP-lowering therapy.
Methods:
Twenty-five eyes of 25 patients with angle closure and IOPs of greater than 30 mmHg were enrolled. Intraocular pressure was measured using RT (iCare Pro), TP (Tono-Pen XL), and GAT before and after medical treatment. The mean IOP readings of the tonometers were compared before and after treatment. The agreement among the tonometers was assessed via Bland-Altman analysis.
Results:
The measurements from 22 eyes of 22 patients were suitable for statistical analyses. Before medical treatment, the mean TP-IOP was significantly lower than the mean GAT-IOP (44.0 ± 10.3 vs. 50.4 ± 8.9 mmHg, respectively; P < .001), but no significant difference was evident between the RT-IOP and the GAT-IOP (50.8 ± 10.9 vs. 50.4 ± 8.9 mmHg, respectively; P = .79). After IOP-lowering treatment, the mean GAT-IOP (14.9 ± 4.7 mmHg) did not differ from either the mean RT-IOP (15.6 ± 4.4 mmHg) or the mean TP-IOP (15.4 ± 5.0 mmHg; P = .05 and P = .18, respectively). The random measurement error among tonometers was greater for high IOP readings.
Conclusions:
Compared with RT or GAT, TP underestimated IOP in angle-closure eyes with a GAT-IOP of greater than 30 mmHg. Intraocular pressure reading agreement among the three tonometers was lower in eyes with high IOP.
More Related Videos
Related Concept Videos
Angle Closure Glaucoma: Treatment
Contact Angle
The adhesive force is the molecular force between molecules of different materials, that is, between the molecules of the solid and the liquid. The cohesive...
The Sense of Self: Reflected Self-Appraisal and Social Comparison
Open Angle Glaucoma: Treatment
Drugs such as carbonic anhydrase inhibitors, α2- and...
Angle of Twist: Problem Solving
Multiple Comparison Tests
It would be easy to compare two samples using a significance alpha level of 0.05. In other words, there is only one sample pair to be compared. However, it would be difficult to identify a significantly different sample if the number...

