[ProTon--a new portable tonometer. Initial experimental and clinical results]

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Devices

Background:

• Intraocular pressure (IOP) measurement is crucial for diagnosing and managing glaucoma.
• Accurate and portable tonometers are needed for efficient clinical practice and remote patient monitoring.
• The Mackay-Marg principle offers a basis for developing new tonometry devices.

Purpose of the Study:

• To evaluate the accuracy and reliability of a new portable tonometer, the ProTon (Tomey), which operates on the Mackay-Marg principle.
• To compare the ProTon tonometer's measurements against manometric IOP values in vitro and Goldmann tonometer measurements in vivo.

Main Methods:

• In vitro: Three human cadaver eyes were cannulated, and intraocular pressure was manometrically determined and compared with ProTon measurements.
• In vivo: 196 eyes from 98 patients were measured using both the ProTon tonometer and the Goldmann tonometer.
• Statistical analysis included correlation coefficients and paired t-tests to assess agreement and significance.

Main Results:

• In vitro, ProTon measurements showed a high correlation (r = 0.99) with manometrically determined IOP values.
• In vivo, ProTon measurements demonstrated good correspondence with Goldmann tonometer readings, with a correlation of r = 0.95.
• The differences between ProTon and Goldmann measurements were statistically significant (P < 0.001), indicating high agreement.

Conclusions:

• The ProTon tonometer, based on the Mackay-Marg principle, is a highly accurate device for measuring intraocular pressure.
• Its performance in both in vitro and in vivo settings suggests it is a reliable and clinically viable alternative to existing tonometers.