Health TrialsbyHealthPanel

Automated Applanation Tonometry - Updated

ConditionsGlaucomaGlaucoma, Suspect
Trial statusRecruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18+
SponsorDuke University

About 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. 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.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

Presenting for a routine eye exam

≥ 18 years of age

Able and willing to give consent

Disqualifiers

History of corneal scarring

Active infection of the eye

Ocular surface trauma or infection

Trial design

Design model

Parallel

Treatments tested in this trial

  • Standard GAT

    Device

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

  • Fixed force GAT

    Device

    An investigational device similar to standard GAT

  • Upright applanating prototype

    Device

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

  • Pneumotonometer

    Device

    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

Treatment groups

200 Participants
are divided into 4 treatment groups
Group A: Standard GATActive comparator 1 intervention
Group B: Fixed-force GATExperimental treatment 1 intervention
Group C: Upright applanating prototypeExperimental treatment 1 intervention
Group D: PneumotonometerActive comparator 1 intervention

Trial outcomes

Primary outcomes

1

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.

Time frame
Baseline
2

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.

Time frame
Baseline
3

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.

Time frame
Baseline
4

Intraocular pressure as measured by supine Pneumotonometer

Time frame
Baseline

Secondary outcomes

Other outcomes

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Duke University

Lead sponsor

Source ClinicalTrials.gov
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