Automated Eye Pressure Measurement for Glaucoma

Overseen By Sarah Jones, MS

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: Duke University

Disqualifiers: Corneal scarring, Active eye infection

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: 2

111 Participants Needed

What You Need to Know Before You Apply

What is the purpose of this trial?

Goldmann Applanation Tonometry (GAT) is considered the clinical gold standard for eye pressure measurements and yet it is known to be a subjective measurement with limited repeatability and limited portability. The purpose of this study is to develop an automated and objective method for performing applanation tonometry using standard ophthalmic equipment as well as using 2 portable prototypes.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications.

Is the automated eye pressure measurement for glaucoma safe for humans?

The Goldmann applanation tonometry (GAT), which is a standard method for measuring eye pressure, is generally considered safe but requires local anesthetics and has some limitations, such as being a contact device. While the safety of automated versions isn't directly addressed, GAT's long-standing use suggests a baseline of safety for similar methods. ^{1 2 3 4 5}

How does the Automated Eye Pressure Measurement for Glaucoma treatment differ from other treatments?

This treatment is unique because it involves automated devices for measuring eye pressure, which can be done without the traditional slitlamp used in Goldmann applanation tonometry (GAT). This makes it more portable and potentially allows for self-measurement, offering convenience and accessibility compared to standard methods. ^{1 2 4 5 6}

What data supports the effectiveness of the treatment Automated Eye Pressure Measurement for Glaucoma?

The research highlights that Goldmann applanation tonometry (GAT) is considered the gold standard for measuring eye pressure, which is crucial for managing glaucoma. The study comparing different tonometers shows that GAT is reliable, suggesting that the treatments using GAT and its prototypes could effectively measure eye pressure in glaucoma patients. ^{2 5 7 8 9}

Who Is on the Research Team?

Joanne Wen, MD

Principal Investigator

Duke Eye Center

Are You a Good Fit for This Trial?

This trial is for adults over 18 who are coming in for a routine eye exam and can give consent. It's not suitable for those with a history of corneal scarring or an active eye infection.

Inclusion Criteria

Able and willing to give consent

Presenting for a routine eye exam

Exclusion Criteria

I have had scarring on my cornea.

I have an active eye infection.

Timeline for a Trial Participant

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Baseline Measurement

Intraocular pressure (IOP) measurements are taken using various methods including Standard GAT, Fixed-force GAT, Upright applanating prototype, and Supine applanating prototype.

1 day

1 visit (in-person)

Follow-up

Participants are monitored for any adverse effects and the effectiveness of the measurement methods.

4 weeks

1 visit (in-person)

What Are the Treatments Tested in This Trial?

Interventions

• Fixed force GAT
• Standard GAT
• Supine Applanating Prototype
• Upright applanating prototype

Trial Overview The study is testing new automated methods to measure eye pressure against the standard Goldmann Applanation Tonometry (GAT). This includes two portable prototypes and aims to make the process more objective and repeatable.

How Is the Trial Designed?

Group I: Upright applanating prototype Experimental Treatment 1 Intervention

With this prototype, an applanating prism (custom manufactured with medical grade acrylic in an ISO-13485 certified facility) is attached to a fixed-force spring that creates a force equivalent to 1.8 or 2.0 on the GAT dial. Blue LED lights on the prototype are used to create the blue illumination similar to the blue light used in clinical practice on the slit lamp or Perkins tonometer. A C-MOS camera is aligned with the GAT prism to image the applanation mires. The eye is given topical fluorescein/anesthetic. Like fixed-force GAT, the GAT prism contacts the eye while the CMOS camera makes a video of the mire appearance. The diameters of the recorded mire images are measured and the IOP is calculated based on the mire diameter

Group II: Supine Applanating Prototype Experimental Treatment 1 Intervention

With this method, a 5 gram clear acrylic cylinder (custom manufactured with medical grade acrylic in an ISO-13485 certified facility) is aligned with the lens of the CMOS camera and the distal tip of the cylinder is illuminated with blue light using an LED similar to the blue light used in clinical practice on the slit lamp or Perkins tonometer. The eye is given topical fluorescein/anesthetic. While the CMOS camera is recording, the 5 gram weight will rest upon the eye and circular applanation mires are recorded. The diameters of the recorded mire images are measured and the IOP is calculated based on the mire diameter

Group III: Fixed-force GAT Experimental Treatment 1 Intervention

From the patient perspective, this method will feel identical to the standard GAT. The eye is given topical fluorescein/anesthetic. The GAT dial is set at 1.8 or 2.0, a C-MOS camera is connected to one of the oculars of the slit lamp machine and under blue light illumination, the GAT prism contacts the eye while the CMOS camera makes a video of the mire appearance through the ocular. The diameters of the recorded mire images are measured and the IOP is calculated based on the mire diameter

Group IV: Standard GAT Active Control 1 Intervention

This is the standard method for IOP measurement in clinical practice

Who Is Running the Clinical Trial?

Duke University

Lead Sponsor

Trials

2,495

Recruited

5,912,000+

Citations

1. United States pubmed.ncbi.nlm.nih.gov

Increase of peak intraocular pressure during sleep in reproduced diurnal changes by posture. [2015]

2. United States pubmed.ncbi.nlm.nih.gov

Repeatability and reproducibility for intraocular pressure measurement by dynamic contour, ocular response analyzer, and goldmann applanation tonometry. [2022]

3. Switzerland pubmed.ncbi.nlm.nih.gov

Comparison of the Icare ic100 Rebound Tonometer and the Goldmann Applanation Tonometer in 1,000 Eyes. [2021]

4. Germany pubmed.ncbi.nlm.nih.gov

[Comparison of precision of the TonoPenXL with the Goldmann and Draeger applanation tonometer in a sitting and recumbent position of the patients -- a clinical study on 251 eyes]. [2009]

5. Switzerland pubmed.ncbi.nlm.nih.gov

Comparative evaluation of Diaton and Goldmann applanation tonometers. [2019]

6. Spain pubmed.ncbi.nlm.nih.gov

Clinical comparison of Pulsair non-contact tonometer and Goldmann applanation tonometer in Indian population. [2022]

7. Switzerland pubmed.ncbi.nlm.nih.gov

How to Measure Intraocular Pressure: An Updated Review of Various Tonometers. [2023]

8. Bosnia and Herzegovina pubmed.ncbi.nlm.nih.gov

Rebound Tonometry over Soft Contact Lenses. [2022]

9. United States pubmed.ncbi.nlm.nih.gov

Goldmann applanation tonometry free of the slitlamp. [2015]