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Automated Applanation Tonometry

Primary Purpose

Glaucoma, Glaucoma, Suspect

Status
Recruiting
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
Standard GAT
Fixed force GAT
Upright applanating prototype
Supine Applanating Prototype
Sponsored by
Duke University
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional diagnostic trial for Glaucoma

Eligibility Criteria

18 Years - undefined (Adult, Older Adult)All SexesDoes not accept healthy volunteers

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

Sites / Locations

  • Duke Eye CenterRecruiting

Arms of the Study

Arm 1

Arm 2

Arm 3

Arm 4

Arm Type

Active Comparator

Experimental

Experimental

Experimental

Arm Label

Standard GAT

Fixed-force GAT

Upright applanating prototype

Supine Applanating Prototype

Arm Description

This is the standard method for IOP measurement in clinical practice

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

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

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

Outcomes

Primary Outcome Measures

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.
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.
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.
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.

Secondary Outcome Measures

Full Information

First Posted
February 2, 2022
Last Updated
November 30, 2022
Sponsor
Duke University
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1. Study Identification

Unique Protocol Identification Number
NCT05235321
Brief Title
Automated Applanation Tonometry
Official Title
Automated Applanation Tonometry
Study Type
Interventional

2. Study Status

Record Verification Date
November 2022
Overall Recruitment Status
Recruiting
Study Start Date
November 21, 2022 (Actual)
Primary Completion Date
April 1, 2024 (Anticipated)
Study Completion Date
April 1, 2024 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Sponsor
Name of the Sponsor
Duke University

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
Yes
Device Product Not Approved or Cleared by U.S. FDA
Yes
Product Manufactured in and Exported from the U.S.
No
Data Monitoring Committee
Yes

5. Study Description

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.
Detailed Description
This is a prospective study. Patients presenting for their scheduled eye appointments will be recruited by verbal communication. Following informed consent, intraocular pressure (IOP) measurements will be made by the following 3 upright methods and 1 supine measurements: Standard Goldmann Applanation Tonometry (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. 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. A similar method using an iPod touch camera has been previously published by this PI (1). 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. The order of the above 3 measurements will be randomized. The 4th measurement will be made with the patient in the supine position. Here, the subject will be reclined in our standard clinical exam chair until the iris plane is parallel to the ground. Supine applanating prototype: 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. A similar method using an iPhone 6 camera has been previously published by this PI (2). The clear cylinder in this study is the same as that used in this prior study.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Glaucoma, Glaucoma, Suspect

7. Study Design

Primary Purpose
Diagnostic
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Model Description
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).
Masking
None (Open Label)
Allocation
Randomized
Enrollment
200 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Standard GAT
Arm Type
Active Comparator
Arm Description
This is the standard method for IOP measurement in clinical practice
Arm Title
Fixed-force GAT
Arm Type
Experimental
Arm Description
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
Arm Title
Upright applanating prototype
Arm Type
Experimental
Arm Description
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
Arm Title
Supine Applanating Prototype
Arm Type
Experimental
Arm Description
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
Intervention Type
Device
Intervention Name(s)
Standard GAT
Intervention Description
Standard Goldmann Applanation Tonometry (GAT): this is the standard method for IOP measurement in clinical practice
Intervention Type
Device
Intervention Name(s)
Fixed force GAT
Intervention Description
An investigational device similar to standard GAT
Intervention Type
Device
Intervention Name(s)
Upright applanating prototype
Intervention Description
An investigational device, prism used in standard and fixed-force GAT is attached to a portable device
Intervention Type
Device
Intervention Name(s)
Supine Applanating Prototype
Intervention Description
An investigational device, prism used in standard and fixed-force GAT is attached to a portable device performed in the supine position
Primary Outcome Measure Information:
Title
Intraocular pressure (IOP) as measured by standard GAT
Description
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.
Time Frame
Baseline
Title
Intraocular pressure (IOP) as measured by fixed force GAT
Description
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.
Time Frame
Baseline
Title
Intraocular pressure as measured by upright applanating
Description
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.
Time Frame
Baseline
Title
Intraocular pressure as measured by supine applanating protoype
Description
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.
Time Frame
Baseline

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility 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
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Sarah Jones, MS
Phone
919-681-6584
Email
sarah.jones1@duke.edu
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Joanne Wen, MD
Organizational Affiliation
Duke Eye Center
Official's Role
Principal Investigator
Facility Information:
Facility Name
Duke Eye Center
City
Durham
State/Province
North Carolina
ZIP/Postal Code
27710
Country
United States
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Joanne Wen, MD
Email
joanne.wen@duke.edu

12. IPD Sharing Statement

Plan to Share IPD
No
IPD Sharing Plan Description
No Currently, there is no plan to share data with other researchers.

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Automated Applanation Tonometry

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