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WaveLight® Refractive Flap Accuracy Study

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Alcon Research
ClinicalTrials.gov Identifier:
NCT01941485
First received: September 10, 2013
Last updated: November 7, 2016
Last verified: November 2016
  Purpose
The purpose of this study is to evaluate the accuracy of the WaveLight FS200 femtosecond laser, as assessed by 1 day and 1 month post-operative optical coherence tomography (OCT) anterior segment corneal measurements compared to pre-operative flap thickness target.

Condition Intervention
Refractive Error
Device: WaveLight® Refractive Suite
Procedure: LASIK surgery

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: A Prospective, Global, Multi-Center Study to Evaluate Longitudinal Flap Accuracy on Subjects Undergoing Myopic Refractive Surgery Using the WaveLight® Refractive Suite

Resource links provided by NLM:


Further study details as provided by Alcon Research:

Primary Outcome Measures:
  • The Difference Between Achieved Flap Thickness at Day 1 Postoperative as Assessed by OCT and Expected Flap Thickness as Determined Pre-operatively [ Time Frame: Day 1 Postoperative ]
    The expected flap thickness as determined pre-operatively was subtracted from the achieved flap thickness at Day 1 postoperative as assessed by optical coherence tomography (ie, an imaging method using light to capture three-dimensional images). Accuracy of flap creation was defined as an achieved thickness within 10 microns of expected thickness.


Secondary Outcome Measures:
  • Incidence of Development of Opaque Bubble Layer (OBL) [ Time Frame: Operation/Surgery (Day 1) ]
    OBL (the collection of gas bubbles during corneal flap creation) was assessed by digital photo analysis of the area covered by the flap and is reported as the percentage of participants with opaque bubble layer development during femtosecond flap creation.

  • Extent of Opaque Bubble Layer (OBL) Within the Femtosecond Flap [ Time Frame: Operation/Surgery (Day 1) ]
    The extent of OBL was assessed by digital photo analysis of the area covered by the flap and is reported as the percentage of flap with opaque bubble layer development during femtosecond flap creation.

  • The Difference Between Achieved Flap Thickness at Month 1 Post-operative as Assessed by OCT and Expected Flap Thickness as Determined Preoperatively [ Time Frame: Month 1 Postoperative ]
    The expected flap thickness as determined pre-operatively subtracted from the achieved flap thickness at Month 1 postoperative as assessed by optical coherence tomography (ie, an imaging method using light to capture three-dimensional images). Accuracy of flap creation was defined as an achieved thickness within 10 microns of expected thickness.

  • Uncorrected Visual Acuity (UCVA) [ Time Frame: Baseline/Screening (Day 0), Day 1 Postoperative, Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    Visual acuity (VA) without spectacles or other visual corrective devices, was performed with an Early Treatment Diabetic Retinopathy Study (ETDRS) chart set at a distance of 4 meters. UCVA was measured in logMAR (logarithm of the minimum angle of resolution), with 0.00 logMAR corresponding to 20/20 Snellen. A lower logMAR value indicates better visual acuity.

  • Best Corrected Visual Acuity (BCVA) [ Time Frame: Baseline/Screening (Day 0), Day 1 Postoperative, Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    VA with the subjects's best spectacles or other visual corrective devices, was performed with an ETDRS chart set at a distance of 4 meters. BCVA was measured in logMAR (logarithm of the minimum angle of resolution), with 0.00 logMAR corresponding to 20/20 Snellen. A lower logMAR value indicates better visual acuity.

  • Manifest Refraction (Sphere) [ Time Frame: Baseline/Screening (Day 0), Day 1 Postoperative, Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    A series of test lenses in graded powers was used to determine which corrective lenses provided the sharpest, clearest vision. Manifest refraction is measured in diopters. Each eye contributed individually to the analysis.

  • Manifest Refraction (Cylinder) [ Time Frame: Baseline/Screening (Day 0), Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    A series of test lenses in graded powers was used to determine which corrective lenses provided the sharpest, clearest vision. Manifest refraction is measured in diopters. Each eye contributed individually to the analysis.

  • Mean Contrast Sensitivity (CS) [ Time Frame: Baseline/Screening (Day 0), Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    Contrast sensitivity (ie, the ability to detect slight changes in luminance before they become indistinguishable) was assessed binocularly with distance manifest correction in place and uncorrected. Contrast sensitivity was assessed at spatial frequencies of 3, 6, 12, and 18 cycles per degree (cpd), where 3.0 cpd = A, 6.0 cpd = B, 12.0 cpd = C, and 18.0 cpd = D. Raw scores were log transformed. A higher numeric value represents better contrast sensitivity. Both eyes contributed to the analysis.

  • Corneal Flap Diameter as Assessed by Ocular Coherence Tomography (OCT) [ Time Frame: Operation/Surgery (Day 1), Day 1 Postoperative, Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    The diameter of the corneal flap was assessed by OCT (ie. an imaging method using light to capture three-dimensional images). Corneal flap is measured in millimeters.

  • Wavefront Aberrometry [ Time Frame: Operation/Surgery (Day 1), Month 1 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    Wavefront aberrations (optical imperfections of the eye that prevent light from focusing perfectly on the retina, resulting in defects in the visual image) were measured using a commercially available system. Higher order aberrations (i.e., spherical aberrations, coma, and trefoil) are defined as optical imperfections which cannot be corrected by any reliable means of present technology.

  • Mean Response: "Rate Your Vision, Over the Past 4 Weeks, With NO Glasses or Contact Lenses" [ Time Frame: Baseline/Screening (Day 0), Month 1 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    As recorded by the subject on the the Refractive Status and Vision Profile (RSVP), a self-reported questionnaire used to measure vision-related health status in persons with refractive error, on a scale from 0 (completely blind) to 10 (perfect vision).

  • Percent Response to "Have Always Worn Glasses or Contact Lenses in the Past 4 Weeks" [ Time Frame: Baseline/Screening (Day 0), Month 1 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    As recorded by the subject on the the Refractive Status and Vision Profile (RSVP), a self-reported questionnaire used to measure vision-related health status in persons with refractive error.

  • Percent Response by Category: "I Worry About my Vision" [ Time Frame: Baseline/Screening (Day 0), Month 1 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    As recorded by the subject on the RSVP questionnaire

  • Percent Response by Category: "My Vision is a Concern in my Daily Life" [ Time Frame: Baseline/Screening (Day 0), Month 1 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    As recorded by the subject on the RSVP questionnaire

  • Percent Response by Category: "Driving at Night" [ Time Frame: Baseline/Screening (Day 0), Month 1 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    As recorded by the subject on the RSVP questionnaire, where 0 is "Not applicable", 1 is "No difficulty at all", 2 is "A little difficulty", 3 is "Moderate difficulty", 4 is "Severe difficulty" and 5 is "So much difficulty that I did not do the activity with this alternative".

  • Corneal Curvature as Measured by Keratometry [ Time Frame: Baseline/Screening (Day 0), 1 Month Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    Corneal curvature as assessed by a commercially available system and measured in diopters.

  • Flap Creation Time as Documented in the Log Files [ Time Frame: Operation/Surgery (Day 1) ]
    The time to create the flap with FS200 Femtosecond Flap Creation System, measured in seconds.

  • Corneal Topography: Q-value [ Time Frame: Day 1 Postoperative, Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    The Q-value (a measure of corneal asphericity) was assessed using a commercially available system. The Q-values are negative (−1 < Q < 0) for prolate corneas, in which the central curvature is steeper than the peripheral curvature, and positive (Q > 0) for oblate corneas, in which the central curvature is flatter than the peripheral curvature.

  • Corneal Topography: Anterior Chamber (AC) Volume [ Time Frame: Day 1 Postoperative, Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    The AC volume (a measure of the shallowness of the anterior chamber) was assessed using a commercially available system. The lower the chamber volume, the more shallow the anterior chamber or the chamber angle.

  • Corneal Topography: Anterior Chamber (AC) Depth [ Time Frame: Day 1 Postoperative, Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    The AC depth (axial distance between the anterior surface of the cornea and the anterior surface of the lens) was assessed using a commercially available system. A higher value represents a longer distance.

  • Corneal Topography: Angles [ Time Frame: Day 1 Postoperative, Month 1 Postoperative, Month 3 Postoperative, Month 6 Postoperative, Month 12 Postoperative ]
    The angles (angular measurement of the space between the iris and the lens) were assessed using a commercially available system. The higher the value, the bigger the space.


Enrollment: 60
Study Start Date: October 2013
Study Completion Date: February 2015
Primary Completion Date: January 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: WaveLight Refractive Suite
LASIK surgery (laser in situ keratomileusis) per standard of care
Device: WaveLight® Refractive Suite
Excimer EX500 and Femtosecond FS200 lasers (Wavelight® Refractive Suite) used during LASIK surgery for corneal flap creation and corneal ablation
Procedure: LASIK surgery
Surgical procedure for treating refractive error based on corneal reshaping

  Eligibility

Ages Eligible for Study:   18 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Willing and able to understand and sign an informed consent form.
  • Have refractive error (in both eyes) that requires refractive surgery.
  • Willing to undergo LASIK surgery using the Wavelight® Refractive Suite.
  • Myopia between 0.00 to -12.0 Diopters pre-operatively.
  • Astigmatism between 0.00 to +6.00 Diopters pre-operatively.
  • Willing and able to attend post-operative examinations per protocol schedule.
  • Other protocol-defined inclusion criteria may apply.

Exclusion Criteria:

  • Participation in a clinical study within the last 30 days.
  • History of previous corneal surgery in either eye.
  • Multifocal ablations in either eye.
  • PRK or PTK surgery in either eye.
  • Suffering from acute or recurring eye diseases in either eye, such as corneal ulcers, cataract, etc.
  • Any ocular disease and/or condition that, in the Investigator's clinical judgment, may put subject at significant risk, compromise study results, or interfere significantly with subject's participation in the study.
  • Unable to discontinue contact lens wear as specified in protocol.
  • History of Herpes simplex or Herpes zoster keratitis.
  • Active ocular rosacea.
  • Lyme disease.
  • Severe ocular allergies.
  • Other medical conditions and use of medications as specified in protocol.
  • Pregnant or planning to become pregnant during the study.
  • Other protocol-specified exclusion criteria may apply.
  Contacts and Locations
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, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01941485

Sponsors and Collaborators
Alcon Research
Investigators
Study Director: Sr. Clinical Manager, GCRA, Global Med Affairs, Operations Alcon Research
  More Information

Responsible Party: Alcon Research
ClinicalTrials.gov Identifier: NCT01941485     History of Changes
Other Study ID Numbers: A01354
Study First Received: September 10, 2013
Results First Received: February 1, 2015
Last Updated: November 7, 2016

Keywords provided by Alcon Research:
nearsighted
astigmatism
LASIK
refractive surgery
WaveLight

Additional relevant MeSH terms:
Refractive Errors
Eye Diseases

ClinicalTrials.gov processed this record on March 29, 2017