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Wavefront-guided PRK vs Wavefront-optimized PRK

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02091934
Recruitment Status : Completed
First Posted : March 19, 2014
Last Update Posted : December 8, 2021
Information provided by (Responsible Party):
Edward E. Manche, Stanford University

Brief Summary:
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

Condition or disease Intervention/treatment Phase
Myopia Astigmatism Procedure: Wavefront-guided PRK Procedure: Wavefront-optimized PRK Not Applicable

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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 71 participants
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: A Prospective, Randomized Comparison of Fellow Eyes Undergoing Wavefront-guided PRK Versus Wavefront-optimized PRK Using the Alcon Allegretto Eye-Q 400 Excimer Laser
Actual Study Start Date : April 1, 2009
Actual Primary Completion Date : March 31, 2012
Actual Study Completion Date : March 31, 2012

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: Wavefront-guided PRK
Wavefront-guided PRK
Procedure: Wavefront-guided PRK
Wavefront-guided PRK
Other Name: Alcon Wavelight Eye-Q 400 wavefront-guided PRK

Active Comparator: Wavefront-optimized PRK
Wavefront-optimized PRK
Procedure: Wavefront-optimized PRK
Wavefront-optimized PRK
Other Name: Alcon Wavelight Eye-Q 400 wavefront-optimized PRK

Primary Outcome Measures :
  1. Uncorrected visual acuity [ Time Frame: One year ]
    Uncorrected visual acuity

Secondary Outcome Measures :
  1. Topographic analysis [ Time Frame: One year ]
    Topographic analysis

  2. Wavefront analysis [ Time Frame: One year ]
    Wavefront analysis

  3. Quality of vision and quality of life questionnaire [ Time Frame: One year ]
    Patient Reported Outcomes Questionnaire

  4. Corneal haze [ Time Frame: One year ]
    Corneal haze

  5. Changes in best corrected 5 and 25% contrast visual acuity [ Time Frame: One year ]
    Changes in best corrected 5 and 25% contrast visual acuity

  6. Changes in best corrected visual acuity [ Time Frame: One year ]
    Changes in best corrected visual acuity

  7. Refractive predictability [ Time Frame: One year ]
    Refractive predictability

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   21 Years to 60 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

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.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02091934

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United States, California
Stanford Eye Laser Center
Palo Alto, California, United States, 94303
Sponsors and Collaborators
Stanford University
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Principal Investigator: Edward E Manche, MD Stanford University
Publications of Results:
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Responsible Party: Edward E. Manche, Professor of Ophthalmology, Stanford University Identifier: NCT02091934    
Other Study ID Numbers: Stanford IRB #29233
First Posted: March 19, 2014    Key Record Dates
Last Update Posted: December 8, 2021
Last Verified: November 2021
Keywords provided by Edward E. Manche, Stanford University:
Additional relevant MeSH terms:
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Refractive Errors
Eye Diseases
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Physiological Effects of Drugs