Recruiting

Investigational Methods

Sponsor:

Duke University

Code:

NCT07298356

Conditions

Glaucoma

Glaucoma, Suspect

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Standard GAT

Fixed force GAT

Upright applanating prototype

Pneumotonometer

Study Details

Brief summary:

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. Another clinical standard for checking eye pressure is known as the pneumotonometer. This method is more objective but not portable. The purpose of this study is to develop new methods of measuring eye pressure that are more objective, reproducible and portable. In this study, the investigators will be comparing the eye pressure measurements using 2 investigational methods to GAT and pneuumotonometer.

Conditions

Glaucoma

Glaucoma, Suspect

Study ID

NCT07298356

Start date

Mar 2, 2026

Status verified date

Dec, 2025

Completion date

Dec 29, 2026

Anticipated

Primary completion date

Dec 29, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Criteria:

Inclusion Criteria:

  • Presenting for a routine eye exam
  • ≥ 18 years of age
  • Able and willing to give consent

Exclusion Criteria:

  • History of corneal scarring
  • Active infection of the eye
  • Ocular surface trauma or infection

Study Design

Enrollment

200 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Diagnostic

Interventions and Outcome Measures

Arms

active comparator: Standard GAT

This is the gold-standard method for IOP measurement in clinical practice

experimental: Fixed-force GAT

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

experimental: Upright applanating prototype

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

active comparator: Pneumotonometer

This is another standard method for IOP measurement in clinical practice

Interventions

Standard GAT

Standard Goldmann Applanation Tonometry (GAT): this is the standard method for IOP measurement in clinical practice

Fixed force GAT

An investigational device similar to standard GAT

Upright applanating prototype

An investigational device, prism used in standard and fixed-force GAT is attached to a portable device

Pneumotonometer

This is a standard for checking eye pressure. A topical anesthetic (numbing agent). A probe will touch the front of the eye while the machine measures the eye pressure

Primary outcome measure

  • Intraocular pressure (IOP) as measured by standard GAT [ Time Frame: Baseline ]
  • Intraocular pressure (IOP) as measured by fixed force GAT [ Time Frame: Baseline ]
  • Intraocular pressure as measured by upright applanating [ Time Frame: Baseline ]
  • Intraocular pressure as measured by supine Pneumotonometer [ Time Frame: Baseline ]

Central Contacts and Locations

Central contacts

Sarah Jones

919 681 6584sarah.jones1@duke.edu

Locations

Duke Eye Center

Recruiting

Durham, North Carolina, United States, 27710

Contacts

Joanne Wen, MD

919-684-2975joanne.wen@duke.edu

Principal Investigator:

Joanne Wen, MD

More Information

Sponsor

Duke University

Last update posted

Mar 6, 2026

Last verified

Dec, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-09. This information was provided to ClinicalTrials.gov by Duke University on 2026-03-06.