Automated Eye Pressure Measurement for Glaucoma

Recruiting in Palo Alto (17 mi)

Overseen byJoanne Wen, MD

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Academic

Recruiting

Sponsor: Duke University

No Placebo Group

Trial Summary

What is the purpose of 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. 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.

Eligibility Criteria

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

I am 18 years old or older.

Presenting for a routine eye exam

Exclusion Criteria

I have had scarring on my cornea.

I have an active eye infection.

Treatment Details

Interventions

Fixed force GAT (Device)
Standard GAT (Device)
Supine Applanating Prototype (Device)
Upright applanating prototype (Device)

Trial OverviewThe 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.

Participant Groups

4Treatment groups

Experimental Treatment

Active Control

Group I: Upright applanating prototypeExperimental Treatment1 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 PrototypeExperimental Treatment1 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 GATExperimental Treatment1 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 GATActive Control1 Intervention

This is the standard method for IOP measurement in clinical practice