Optical Coherence Tomography Guided Transepithelial Phototherapeutic Keratectomy

February 8, 2024 updated by: David Huang, Oregon Health and Science University
Optical Coherence Tomography (OCT) machines are non-contact instruments that can measure the depth of scars and other causes of cloudiness in the front of the cornea. The purpose of this study is to determine whether OCT-guided settings for the lasers used for removal of corneal scars and other partial-thickness corneal defects result in improved vision in patients receiving these procedures.

Study Overview

Status

Recruiting

Conditions

Detailed Description

The long-term goal of this project is to utilize newly available very high-speed OCT technology to guide surgical treatments of corneas with superficial opacities and irregularities. OCT is well known for its exquisite resolution, but until recently it has not had sufficient speed to capture the shape of the cornea because of eye motion during OCT scanning. The development of Fourier-domain OCT (FD-OCT) technology has made the requisite speed possible.

Eyes with superficial opacities (corneal scars and stromal dystrophies) can be treated by phototherapeutic keratectomy (PTK). Currently, many surgeons rely on subjective slit-lamp impression of opacity depth to guide PTK and repeat slit-lamp examinations during surgery to determine if the opacity has been sufficiently reduced. Unpredictable hyperopic shifts can occur after PTK. The aim of this project is to develop methods for imaging the cornea with an FD-OCT system that will precisely measure corneal shape and use this information to guide surgery. Patients with irregularly shaped corneas could have their vision restored by reshaping the corneas with a procedure that combines the precision of OCT and lasers.

Study Type

Interventional

Enrollment (Estimated)

80

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

    • Oregon
      • Portland, Oregon, United States, 97239
        • Recruiting
        • Casey Eye Institute, Oregon Health & Science University
        • Contact:
        • Contact:
        • Principal Investigator:
          • David Huang, MD, PhD
        • Sub-Investigator:
          • Winston Chamberlain, MD, PhD
        • Sub-Investigator:
          • Afshan Nanji, MD
        • Sub-Investigator:
          • Richard Stutzman, MD
        • Sub-Investigator:
          • Yan Li, PhD
        • Sub-Investigator:
          • Ellen Davis, MD
        • Sub-Investigator:
          • Seema Gupta, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Patients with vision primarily limited by superficial opacities and irregularities that could be removed by PTK while leaving at least 250 µm.

Exclusion Criteria:

  • Inability to give informed consent
  • Inability to maintain stable fixation for OCT imaging
  • Inability to commit to required visits to complete the study
  • Deep corneal opacities and irregularities
  • Cataracts, retinal disease, glaucoma, or other eye conditions that may limit the visual outcome after surgery

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Surgery
OCT is assisting in surgery guidance.
Preoperative measurements from the OCT are used to assist the calculation in deciding the laser depth settings for removal of anterior corneal opacities and defects in the phototherapeutic PTK procedure. The surgeon uses the OCT data to plan a range of treatment parameters to remove most of the opacity while preserving at least 250 microns of residual corneal stroma.
Other Names:
  • Manufacturer/Name OCT Technology 510(K)
  • Optovue/RTVue-CAM Fourier-domain K071250
  • Bioptigen/Bioptigen Fourier-domain K063343
  • Zeiss/Visante Time-domain K051789

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Improvement in best spectacle-corrected visual acuity (BSCVA) after PTK
Time Frame: 12 months post-procedure
The primary goal of the trial is to determine the efficacy of the OCT-guided PTK treatment of corneal opacities. During the course of the trial, we will compare the predictive accuracy of the original OCT-guided PTK planning system to the OCT topography-guided system. BSCVA will be measured in typical Snellen acuity notation as 20/xx (feet)
12 months post-procedure

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Improvement in uncorrected visual acuity (UCVA), refractive error, and higher order aberrations
Time Frame: 12 months post-procedure
A second goal is to develop a more sophisticated OCT guidance system incorporating OCT topography of anterior and posterior corneal surfaces and to develop a mathematical model that relates epithelial thickness variation to corneal mean curvature. During the course of the trial, we will compare the predictive accuracy of the original OCT-guided PTK planning system to the OCT topography-guided system. UCVA will be measured in typical Snellen acuity notation as 20/xx (feet)
12 months post-procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: David Huang, MD, PhD, Casey Eye Institute, Oregon Health & Science University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

June 1, 2011

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

November 18, 2010

First Submitted That Met QC Criteria

November 18, 2010

First Posted (Estimated)

November 19, 2010

Study Record Updates

Last Update Posted (Actual)

February 12, 2024

Last Update Submitted That Met QC Criteria

February 8, 2024

Last Verified

February 1, 2024

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • OHSU IRB #00006612-PTK
  • R01EY018184 (U.S. NIH Grant/Contract)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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