Principles of contact lens tonometry

Area of Science:

• Ophthalmology
• Biomedical Engineering
• Medical Devices

Background:

• Accurate intraocular pressure (IOP) measurement is crucial for diagnosing and managing glaucoma.
• Current methods can be influenced by the force applied during measurement (appositional force).
• A need exists for a device that can measure IOP independently of appositional force.

Purpose of the Study:

• To develop and evaluate a contact lens with an integrated pressure-sensing device.
• To assess the device's ability to measure IOP independent of appositional force (p0).
• To investigate continuous IOP monitoring and IOP variations related to appositional force.

Main Methods:

• Construction of a contact lens with a three-point force-sensing element system.
• Precision testing against a manometric transducer using eye bank eyes.
• Examination of IOP as a function of appositional force and development of a measurement procedure for baseline eye pressure (p0).

Main Results:

• The contact lens device demonstrated precision in measuring appositional force.
• The study established a method for measuring baseline eye pressure (p0) independent of appositional force.
• The device allows for continuous IOP monitoring and assessment of IOP dependency on appositional force.

Conclusions:

• The developed contact lens offers a promising new method for accurate IOP measurement.
• This technology has the potential to improve glaucoma diagnosis and patient management.
• The device enables differentiation between pressure-independent and pressure-dependent IOP measurements.