Related Experiment Video
Updated: Jun 16, 2026
08:27
Quantification of Oculomotor Responses and Accommodation Through Instrumentation and Analysis Toolboxes
Published on: March 3, 2023
Optimizing the calibration and interpretation of dynamic ocular force measurements
William H Morgan1, Stephen J Cringle, Min H Kang
1ARC Center of Excellence in Vision Science, Centre for Ophthalmology and Visual Science, The University of Western Australia, 2 Verdun St, Nedlands, WA, Australia. whmorgan@cyllene.uwa.edu.au
Summary
This study developed a new ophthalmodynamometer (OcuDyn) for more accurate intraocular pressure (IOP) measurements. The OcuDyn and Meditron devices demonstrated improved reproducibility for assessing ocular vascular pressures.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Medical Device Development
Background:
- Ophthalmodynamometry offers insights into glaucoma, cerebrospinal fluid pressure, and vascular disease.
- Current methods suffer from variable reproducibility and lack of force calibration in relation to intraocular pressure (IOP).
- This study aimed to establish calibration factors and identify key design principles for ophthalmodynamometers.
Purpose of the Study:
- To develop and validate a novel ophthalmodynamometer, OcuDyn, for improved accuracy and reproducibility.
- To calculate calibration factors for different ophthalmodynamometer devices.
- To identify design principles that enhance the reliability of ophthalmodynamometric measurements.
Main Methods:
- A modified ophthalmodynamometer, OcuDyn, was constructed using a contact lens and force transducer.
- Isolated pig eyes and human participants were used to measure induced intraocular pressure (IOP) against applied force.
- Three devices (OcuDyn, Sisler, Meditron) were tested to determine the minimum ophthalmodynamometric force (ODF) for inducing pulsation.
Main Results:
- A strong linear relationship was observed between induced IOP and ODF in both porcine (r > 0.98) and human eyes (r = 0.83).
- OcuDyn and Meditron showed significantly lower coefficients of variation (5.6-12.4%) compared to the Sisler device (20%).
- Calibration factors were determined: 0.32 mmHg/g for OcuDyn, 0.89 mmHg/arbitrary unit for Meditron, and 0.82 mmHg/g for Sisler.
Conclusions:
- The linearity between induced IOP and ODF supports the use of calibration factors for accurate pressure estimation.
- OcuDyn and Meditron offer superior optical properties leading to more repeatable endpoint determination.
- Calculated calibration factors can aid in estimating ocular vascular, orbital, and cerebrospinal fluid pressures.
