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Goldmann applanation tonometry and Perkins tonometry significantly underestimate true intracameral IOP

Intraocular pressure (IOP) is a key objective measure in the diagnosis and treatment of glaucoma.
Goldmann Applanation Tonometry currently remains the gold standard for IOP measurements,
however as the below reference paper entitled “Goldmann applanation tonometry error relative
to true intracameral intraocular pressure in vitro and in vivo” discusses, there are overall bias and
biomechanical errors in Goldmann tonometer readings. This is due to the variability in corneal biomechanics.
The debate exists regarding the amount of errors, as it is difficult to quantify, but Goldmann applanation
tonometry and Perkins tonometry significantly underestimate true intracameral IOP.

The Goldmann-type tonometer error measured on live human eyes was 5.2 +/−1.6 mmHg lower
than intracameral IOP in the upright position and 7.9 +/− 2.3 mmHg lower in the supine position (p < .05).
CCT also indicated a sloped correlation to error (correlation coeff. = 0.18). Goldmann IOP measures
significantly lower than true intracameral IOP by approximately 3 mmHg in vitro and 5 mmHg in vivo.
The Goldmann IOP error is increased an additional 2.8 mmHg lower in the supine position.

Eye C Better is well on the way to substantially reducing the existing error in IOP measurements
while simultaneously being able to take the measurements in a non-contact fashion.

To read the full article, please see the below link:


Eye C Better (ECB) is a Medical Technology as a Service (MedTaaS) company that combines a
breakthrough medical device with digital technology to transform glaucoma healthcare.
People with glaucoma continue to need care when they leave the doctor’s office and Eye C Better
provides individuals with the tools to manage, monitor and maintain their disease.
Glaucoma is caused by elevated eye pressure which damages the optic nerve.
Keeping that pressure within an acceptable range is critical to stopping this blinding disease.
Current glaucoma treatment plans typically have a patient only measuring their pressure a few times a year,
their pressure can fluctuate up to 10mmHg per day and the current device can have accuracy challenges
resulting in up to a 10mmHg misreading or more. Yet a doctor will change their treatment based on a 1 mmHg
change in pressure. Our device will be able to gather numerous pressure measurements throughout a
typical day allowing a doctor to better understand a patient’s eye pressure, effectiveness of eye-drops,
and be able to make better recommendations to measure, monitor, and maintain healthy eye pressures.
More eye pressure measurements will lead to better patient outcomes and help those people with
glaucoma enjoy a lifetime of vision.

To learn more about Eye C Better Corp., visit
Main Phone: 669-244-5849