Optical Coherence Tomography Guided Transepithelial Phototherapeutic Keratectomy
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 Design:||Allocation: Non-Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Optical Coherence Tomography Guided Transepithelial Phototherapeutic Keratectomy|
- Improvement in best spectacle-corrected visual acuity (BSCVA) after PTK [ Time Frame: 3-4, 6-8, and 12-14 months after the PTK procedure ] [ Designated as safety issue: No ]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.
- Improvement in uncorrected visual acuity (UCVA), refractive error, and higher order aberrations [ Time Frame: 3-4, 6-8, and 12-14 months after the PTK procedure ] [ Designated as safety issue: No ]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.
|Study Start Date:||June 2011|
|Estimated Study Completion Date:||July 2016|
|Estimated Primary Completion Date:||July 2016 (Final data collection date for primary outcome measure)|
Drug: OCT-guided laser phototherapeutic keratectomy
- Manufacturer/Name OCT Technology 510(K)
- Optovue/RTVue-CAM Fourier-domain K071250
- Bioptigen/Bioptigen Fourier-domain K063343
- Zeiss/Visante Time-domain K051789
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.
|Contact: Janice Van Normanfirstname.lastname@example.org|
|United States, Oregon|
|Casey Eye Institute, Oregon Health & Science University||Recruiting|
|Portland, Oregon, United States, 97239|
|Contact: Janice Van Norman 503-494-8024 email@example.com|
|Contact: Michelle Montalto 503-494-1616 firstname.lastname@example.org|
|Principal Investigator: Frederick (Rick) W. Fraunfelder, MD|
|Principal Investigator:||Frederick (Rick) W. Fraunfelder, MD||Casey Eye Institute, Oregon Health & Science University|