Evaluation of the new Ocuton S tonometer

Area of Science:

• Ophthalmology
• Glaucoma diagnostics
• Intraocular pressure measurement

Background:

• Accurate intraocular pressure (IOP) measurement is crucial for diagnosing and managing glaucoma.
• The Ocuton S tonometer offers a potential alternative for IOP assessment.
• Evaluating new tonometry devices against established standards like Goldmann tonometry is essential.

Purpose of the Study:

• To assess the Ocuton S tonometer's intra- and interobserver variability.
• To compare Ocuton S tonometer readings with Goldmann tonometry.
• To evaluate the reliability of patient self-tonometry using the Ocuton S and its safety.

Main Methods:

• The study included 35 healthy subjects and 45 patients with primary open-angle glaucoma (POAG).
• Tonometry was performed using the Ocuton S and Goldmann tonometers, with central ultrasonic pachymetry, keratometry, and biomicroscopy also evaluated.
• Intra- and interobserver variability and self-tonometry reliability were assessed in subgroups.

Main Results:

• Intra- and interobserver variability for the Ocuton S ranged from 0.38 to 0.66.
• Ocuton S consistently overestimated IOP compared to Goldmann tonometry (24.4 mmHg vs 18.1 mmHg, p < 0.0001).
• A significant correlation was found between corneal thickness and IOP for both devices (r ≈ 0.52, p < 0.02). Self-tonometry showed no significant difference from expert measurements.

Conclusions:

• The Ocuton S tonometer is safe and can be used by patients for self-measurement.
• The device overestimates IOP relative to the Goldmann tonometer.
• Further technical and methodological refinements are needed to enhance the Ocuton S tonometer's clinical reliability.