Wavefront-guided PRK vs Wavefront-optimized PRK

November 24, 2021 updated by: Edward E. Manche, Stanford University

A Prospective, Randomized Comparison of Fellow Eyes Undergoing Wavefront-guided PRK Versus Wavefront-optimized PRK Using the Alcon Allegretto Eye-Q 400 Excimer Laser

The purpose of the study is to compare the results of PRKK surgery when using wavefront-guided excimer laser treatment compared to wavefront optimized excimer laser treatment in patients with nearsightedness with and without astigmatism

Study Overview

Detailed Description

This is a research study comparing the outcomes of PRK surgery for nearsightedness when using the two different excimer laser technologies. Patients will have both eyes treated with the Alcon WaveLight Allegretto excimer laser. You will be one of 50 sighted patients at Stanford to undergo treatment in this clinical research trial. This will be a prospective, randomized, research study in which up to 100 consecutive eyes scheduled to undergo excimer laser photo refractive keratectomy (PRK) using one laser technology in the first eye and the second laser technology in the fellow eye for the correction of myopia (nearsightedness) with or without astigmatism will be enrolled. The choice of which eye receives the wavefront guided technology and which eye receives the wavefront-optimized technology will be randomized prior to enrollment. Randomization will be done according to a randomization schedule. You will not know which eye is being treated with which each technology. The randomization will determine only whether your right or left eye is treated with the wavefront guided technology. The other eye will be treated with wavefront-optimized laser technology. You have a fifty percent chance of having your left eye treated with custom wavefront guided technology as your right eye. Subjects will undergo bilateral (both eyes at once) PRK treatments using the Alcon WaveLight Allegretto excimer laser. All subjects will be followed for one year after the vision correction procedure. Subjects scheduled to undergo PRK for the correction of myopia (nearsightedness) with or without astigmatism will be screened for eligibility. Eligible subjects will be examined preoperatively to establish a baseline for ocular condition (the general health and glasses prescription of the eyes). Postoperatively, subjects will undergo an ophthalmic evaluation (complete eye examination) at regular intervals as specified in this protocol. Patients will complete questionnaires preoperatively and postoperatively evaluating quality of vision and quality of life. Retreatments (a second operation on the same eye for residual nearsightedness) will not be allowed during the first twelve months of this study. If you elect to undergo a retreatment of your PRK surgery prior to the 12-month post-operative visit, the retreated eye will be exited from the study as of the retreatment date.

Any significant new finding developed during the course of the research which may relate to the subject's willingness to continue participation will be provided to the subject or subject's representative in a timely manner.

Study Type

Interventional

Enrollment (Actual)

71

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 Locations

    • California
      • Palo Alto, California, United States, 94303
        • Stanford Eye Laser Center

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

19 years to 58 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Subjects age 21 and older with healthy eyes.
  • Nearsightedness between -0.25 diopters and -8.00 diopters with or without astigmatism of up to 5.00 diopters.

Exclusion Criteria:

  • Subjects under the age of 21.
  • Excessively thin corneas.
  • Topographic evidence of keratoconus.
  • Ectactic eye disorders.
  • Autoimmune diseases.
  • Pregnant or nursing.
  • Patients must have similar levels of nearsightedness in each eye. They can not be more than 2.5 diopter of difference between eyes.
  • Patients must have similar levels of astigmatism in each eye. They can not have more than 1.5 diopter of difference between eyes.

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: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Wavefront-guided PRK
Wavefront-guided PRK
Other Names:
  • Alcon Wavelight Eye-Q 400 wavefront-guided PRK
Active Comparator: Wavefront-optimized PRK
Wavefront-optimized PRK
Other Names:
  • Alcon Wavelight Eye-Q 400 wavefront-optimized PRK

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Uncorrected visual acuity
Time Frame: One year
Uncorrected visual acuity
One year

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Topographic analysis
Time Frame: One year
Topographic analysis
One year
Wavefront analysis
Time Frame: One year
Wavefront analysis
One year
Quality of vision and quality of life questionnaire
Time Frame: One year
Patient Reported Outcomes Questionnaire
One year
Corneal haze
Time Frame: One year
Corneal haze
One year
Changes in best corrected 5 and 25% contrast visual acuity
Time Frame: One year
Changes in best corrected 5 and 25% contrast visual acuity
One year
Changes in best corrected visual acuity
Time Frame: One year
Changes in best corrected visual acuity
One year
Refractive predictability
Time Frame: One year
Refractive predictability
One year

Collaborators and Investigators

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

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

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 (Actual)

April 1, 2009

Primary Completion (Actual)

March 31, 2012

Study Completion (Actual)

March 31, 2012

Study Registration Dates

First Submitted

March 9, 2014

First Submitted That Met QC Criteria

March 18, 2014

First Posted (Estimate)

March 19, 2014

Study Record Updates

Last Update Posted (Actual)

December 8, 2021

Last Update Submitted That Met QC Criteria

November 24, 2021

Last Verified

November 1, 2021

More Information

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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