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

What You Need to Know Before You Apply

What is the purpose of this trial?

This trial aims to find a better way to measure eye pressure in people with glaucoma. Researchers are testing new, portable devices to determine if they provide more accurate and reliable results than the traditional method, which can be subjective and inconsistent. The study includes different groups, each using a unique method or device, such as the Fixed force GAT, Standard GAT, Supine Applanating Prototype, and Upright Applanating Prototype. All aim to improve eye pressure measurement. Individuals visiting for a routine eye exam, with no history of corneal scarring or active eye infections, might be suitable for this trial. As an unphased trial, it offers participants the chance to contribute to innovative research that could enhance eye care for many.

Will I have to stop taking my current medications?

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

What prior data suggests that these automated eye pressure measurement methods are safe?

Research has shown that Goldmann Applanation Tonometry (GAT) is a trusted method for measuring eye pressure and is commonly used to manage glaucoma. Most people tolerate it well, and serious side effects are rare.

The fixed force GAT method aims to enhance this standard by using a set force. Studies indicate it provides results similar to the standard GAT, suggesting it is just as safe. Patients experience it similarly, with no new risks reported.

For the supine applanating prototype, some studies mention potential concerns about eye abrasions when lying down. However, these concerns are theoretical, and no significant issues have been reported. The device uses a gentle weight to measure eye pressure, similar to existing tools, and should be safe for most users.

Lastly, the upright applanating prototype uses a custom prism to measure eye pressure. While specific data on this model is limited, similar devices have shown good safety records. It is expected to be as safe as other applanation devices, which are generally well-tolerated.

In summary, all these methods aim to improve eye pressure measurement and appear to have a safety profile similar to existing tools. ^{1 2 3 4 5}

Why are researchers excited about this trial?

Researchers are excited about this trial because it explores advanced methods for measuring eye pressure in glaucoma patients using innovative techniques. While the standard Goldmann Applanation Tonometry (GAT) is commonly used, these prototypes aim to make the process more precise and user-friendly. The fixed-force GAT and upright applanating prototypes incorporate CMOS cameras to record mire images, potentially offering more accurate intraocular pressure (IOP) readings. Meanwhile, the supine applanating prototype uses a custom acrylic cylinder for pressure measurement while lying down, which might improve comfort and accuracy in different patient positions. These advancements could lead to better glaucoma management by offering more reliable and comfortable eye pressure measurement.

What evidence suggests that this trial's methods for automated eye pressure measurement could be effective for glaucoma?

Research has shown that checking eye pressure is crucial for managing glaucoma. In this trial, participants may use different methods to measure eye pressure. The Fixed-force GAT aims to measure this pressure more consistently. Studies indicate that accurate eye pressure checks can help slow glaucoma progression, preventing vision loss. The Supine Applanating Prototype and the Upright Applanating Prototype are also being tested. Both automatically measure eye pressure, potentially increasing reliability. Accurate and consistent measurements are vital for adjusting treatments to improve outcomes. These prototypes are expected to serve as dependable alternatives to traditional methods. ^{1 3 4 6 7}

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. researchgate.net researchgate.net/publication/379728849_A_Comparative_Study_on_Efficacy_of_Intraocular_Pressure_Lowering_of_Two_Fixed-Dose_Antiglaucoma_Drug_Combination_Brinzolamide-Brimonidine_Versus_Latanoprost-Timolol_in_Primary_Open-Angle_Glaucoma_and_

A Comparative Study on Efficacy of Intraocular Pressure ... At 1 month, Group A exhibited a mean IOP of 18.7 mm Hg, while Group B had 17.6 mm Hg, with no statistically significant difference (P = 0.53). No significant ...

2. nature.com nature.com/articles/srep42067

Agreement of patient-measured intraocular pressure using ... This study aims to determine the agreement of patient-measured intraocular pressure (IOP) using rebound tonometry with ophthalmologist-measured IOP using ...

3. sciencedirect.com sciencedirect.com/science/article/pii/S1350946224000685

The relationship between intraocular pressure and glaucoma Both untreated and undertreated glaucoma result in faster disease progression, with greater potential for permanent vision loss and disability.

4. sciencedirect.com sciencedirect.com/science/article/abs/pii/S0039625722000388

Review article Intraocular pressure measurement: A review Intraocular pressure measurement focuses on three methods: transpalpebral measurement, tonometry, and manometry.

5. pmc.ncbi.nlm.nih.gov pmc.ncbi.nlm.nih.gov/articles/PMC8456330/

How to Measure Intraocular Pressure: An Updated Review of ... A recent study comparing iCare with GAT in 1000 eyes showed larger mean differences between tonometers in eyes with IOP > 22 mmHg and in the group of glaucoma ...

6. ncbi.nlm.nih.gov ncbi.nlm.nih.gov/books/NBK493225/

Tonometry - StatPearls - NCBI Bookshelf GAT currently remains the gold standard technique in measuring IOP, especially in managing patients with OHT, risk factors, and in therapy for glaucoma.

7. aaojournal.org aaojournal.org/article/S0161-6420(25)00075-2/fulltext

Long-term Safety and Performance of a Suprachoroidal ... ... Goldmann applanation tonometry (GAT) from month 12 to month 36 after implantation. Secondary safety end points included the incidence, nature, severity, and ...