Portland, Oregon 97239


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 summary:

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.


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 is Available At:

Original ID:

OHSU IRB #00006612-PTK



Secondary ID:


Study Acronym:

Brief Title:

Optical Coherence Tomography Guided Transepithelial Phototherapeutic Keratectomy

Official Title:

Optical Coherence Tomography Guided Transepithelial Phototherapeutic Keratectomy

Overall Status:


Study Phase:




Minimum Age:

18 Years

Maximum Age:


Quick Facts

Healthy Volunteers
Oversight Has DMC
Study Is FDA Regulated
Study Is Section 801
Has Expanded Access

Study Source:

Oregon Health and Science University

Oversight Authority:

United States: Institutional Review Board

Reasons Why Stopped:

Study Type:


Study Design:

Number of Arms:


Number of Groups:


Total Enrollment:


Enrollment Type:


Overall Contact Information

Official Name:David Huang, MD, PhD
Principal Investigator
Casey Eye Institute, Oregon Health & Science University
Primary Contact:Omkar Thaware, B Optom, MSVS
Backup Contact:Denny Romfh, OD

Study Dates

Start Date:June 2011
Completion Date:December 2022
Completion Type:Anticipated
Primary Completion Date:December 2022
Primary Completion Type:Anticipated
Verification Date:May 2019
Last Changed Date:May 1, 2019
First Received Date:November 18, 2010

Study Outcomes

Outcome Type:Primary Outcome
Measure:Improvement in best spectacle-corrected visual acuity (BSCVA) after PTK
Time Frame:12 months post-procedure
Safety Issues:False
Description: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-g
Outcome Type:Secondary Outcome
Measure:Improvement in uncorrected visual acuity (UCVA), refractive error, and higher order aberrations
Time Frame:12 months post-procedure
Safety Issues:False
Description: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

Study Interventions

Intervention Type:Drug
Name:OCT-guided laser phototherapeutic keratectomy
Description: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.
Arm Name:Surgery
Other Name:Manufacturer/Name OCT Technology 510(K)

Study Arms

Study Arm Type:Experimental
Arm Name:Surgery
Description:OCT is assisting in surgery guidance.

Study Agencies

Agency Class:Other
Agency Type:Lead Sponsor
Agency Name:Oregon Health and Science University
Agency Class:NIH
Agency Type:Collaborator
Agency Name:National Eye Institute (NEI)

Sample and Retention Information

There are no available Sample and Retention Information

Study References

There are no available Study References

Data Source: ClinicalTrials.gov

Date Processed: October 09, 2019

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