Automated Applanation Tonometry

NCT05235321 | Terminated DMC FDA Device

• 1 other identifier: Pro00106111
• Study Type: interventional
• Target: 111
• Locations: 1 country
• Sites: 1

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. 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.

Conditions

Glaucoma; Glaucoma, Suspect

Outcome Measures

Primary Outcomes (4)

• Intraocular pressure (IOP) as measured by standard GAT

  this is the standard method for IOP measurement in clinical practice. The eye is given topical fluorescein/anesthetic, the GAT prism contacts the eye while the observer looks through the slit lamp machine ocular using blue light illumination to visual the applanation mires. The GAT dial is adjusted until mire alignment is achieved and the IOP measurement is read off the GAT dial.

  Baseline

• Intraocular pressure (IOP) as measured by 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.

  Baseline

• Intraocular pressure as measured by upright applanating

  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.

  Baseline

• Intraocular pressure as measured by supine applanating protoype

  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.

  Baseline

Study Arms (4)

Standard GAT

ACTIVE COMPARATOR

This is the standard method for IOP measurement in clinical practice

Device: Standard GAT

Fixed-force GAT

EXPERIMENTAL

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

Device: Fixed force GAT

Upright applanating prototype

EXPERIMENTAL

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

Device: Upright applanating prototype

Supine Applanating Prototype

EXPERIMENTAL

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

Device: Supine Applanating Prototype

Interventions

Standard GAT DEVICE

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

Standard GAT

Fixed force GAT DEVICE

An investigational device similar to standard GAT

Fixed-force GAT

Upright applanating prototype DEVICE

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

Upright applanating prototype

Supine Applanating Prototype DEVICE

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

Supine Applanating Prototype

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• History of corneal scarring
• Active infection of the eye

Sponsors & Collaborators

• Duke University: lead

Study Sites (1)

Duke Eye Center

Durham, North Carolina, 27710, United States

Location

MeSH Terms

Conditions

Glaucoma; Ocular Hypertension

Condition Hierarchy (Ancestors)

Eye Diseases

Study Officials

• Joanne Wen, MD

  Duke Eye Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: In this study, 3 eye pressure measurements will be made in the upright position (standard GAT, fixed force GAT, upright applanating prototype) and 1 in the supine position (supine applanating prototype).

Study Record Dates

• First Submitted: February 2, 2022
• First Posted: February 11, 2022
• Study Start: November 21, 2022
• Primary Completion: May 31, 2024
• Study Completion: May 31, 2024
• Last Updated: June 13, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)