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Measurement Repeatability in Contemporary Aberrometry

Primary Purpose

Refractive Errors

Status
Unknown status
Phase
Not Applicable
Locations
Study Type
Interventional
Intervention
Peramis aberrometry
iDesign aberrometry
Sponsored by
Moorfields Eye Hospital NHS Foundation Trust
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional diagnostic trial for Refractive Errors

Eligibility Criteria

21 Years - 60 Years (Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • Myopic LASIK candidates (manifest refraction spherical equivalent range 0 to -10 diopters with up to 6 diopters cylinder) or patients attending corneal service with stage II-III keratoconus or post-keratoplasty

Exclusion Criteria:

  • Visually significant co-pathology (CDVA<6/6) other than irregular astigmatism;
  • Patients unable to complete a sequence of 2 good scans (acquisition diameter >5mm) in one eye within 4 attempts

Sites / Locations

    Arms of the Study

    Arm 1

    Arm 2

    Arm 3

    Arm 4

    Arm Type

    Experimental

    Active Comparator

    Experimental

    Active Comparator

    Arm Label

    Myopia (Peramis)

    Myopia (iDesign)

    Irregular astigmatism (Peramis)

    Irregular astigmatism (iDesign)

    Arm Description

    Peramis aberrometry: 30 consecutive LASIK candidates with myopia and regular astigmatism who agree to participate in the study will have up to 4 aberrometry scans acquired consecutively using the Peramis (test) aberrometer.

    iDesign aberrometry: The same 30 consecutive LASIK candidates scanned in the Myopia (Peramis) arm will also have up to 4 aberrometry scans acquired consecutively using the iDesign aberrometer (control) aberrometer. The order of scans (Peramis and iDesign) will be randomised.

    Peramis aberrometry: 30 consecutive cases with stage II-III keratoconus or post corneal transplantation cases with irregular astigmatism will have up to 4 aberrometry scans acquired consecutively using the Peramis (test) aberrometer

    iDesign aberrometry: 30 consecutive cases with stage II-III keratoconus or post corneal transplantation cases with irregular astigmatism will also have up to 4 aberrometry scans acquired consecutively using the iDesign aberrometer (control) aberrometer. The order of scans (Peramis and iDesign) will be randomised.

    Outcomes

    Primary Outcome Measures

    2nd to 4th order aberrations (5mm pupil).
    M, J0, J45, Coma, Trefoil, Spherical Aberration. Different types of defocus or aberration can be defined and measured by wavefront scanning. Aberrations are classified and quantified by a mathematical treatment called Zernike analysis in which harmonic elements of the waveform of the light detected by the wavefront sensor (aberrometer) are quantified in sequence, starting with simple (lower order) waveforms such as sphere and cylinder (M, J0, J45) corrected in a normal spectacle prescription, and progressing through more complex (higher order) waveforms including, coma, trefoil and spherical aberration which may influence quality of vision. The amount of each aberration varies as a function of pupil size. So pupil size is standardised at 5mm diameter for quantification.

    Secondary Outcome Measures

    % of patients with qualifying scan sequence
    % of patients in whom two 5mm diameter aberrometry scans can be acquired within 4 attempts

    Full Information

    First Posted
    February 7, 2016
    Last Updated
    February 19, 2016
    Sponsor
    Moorfields Eye Hospital NHS Foundation Trust
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    1. Study Identification

    Unique Protocol Identification Number
    NCT02687022
    Brief Title
    Measurement Repeatability in Contemporary Aberrometry
    Official Title
    A Comparative Study of Measurement Repeatability for Two Aberrometers
    Study Type
    Interventional

    2. Study Status

    Record Verification Date
    February 2016
    Overall Recruitment Status
    Unknown status
    Study Start Date
    March 2016 (undefined)
    Primary Completion Date
    June 2016 (Anticipated)
    Study Completion Date
    September 2016 (Anticipated)

    3. Sponsor/Collaborators

    Responsible Party, by Official Title
    Principal Investigator
    Name of the Sponsor
    Moorfields Eye Hospital NHS Foundation Trust

    4. Oversight

    Data Monitoring Committee
    No

    5. Study Description

    Brief Summary
    Wavefront scans are a common form of diagnostic test applied in preparing patients for laser eye surgery. An optical map of the eye is created by wavefront scanning, and information from these maps is used to program lasers used to correct focusing errors in the eye. Here the investigators are comparing how repeatable measurements are with a new wavefront scanner and one that is already in widespread use.
    Detailed Description
    Aberrometers are used to measure each element of defocus (aberration) in an optical system. In LASIK, information derived from aberrometry (scans performed using aberrometers) is used to program the pattern of laser pulses delivered by an excimer laser in therapeutic reshaping of the cornea to correct defocus. To do this accurately, aberrometry findings need to be repeatable and correspond closely to manifest refraction. Here the investigators compare repeatability of measurements for a new aberrometer (Peramis) versus the aberrometer most widely used in contemporary wavefront guided laser vision correction (iDesign). The test aberrometer will be: Peramis (Schwind Eye-tech Solutions, Kleinostheim, Germany). Control aberrometer will be: iDesign (AMO, Santa Clara, CA)

    6. Conditions and Keywords

    Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
    Refractive Errors

    7. Study Design

    Primary Purpose
    Diagnostic
    Study Phase
    Not Applicable
    Interventional Study Model
    Parallel Assignment
    Masking
    Investigator
    Allocation
    Randomized
    Enrollment
    60 (Anticipated)

    8. Arms, Groups, and Interventions

    Arm Title
    Myopia (Peramis)
    Arm Type
    Experimental
    Arm Description
    Peramis aberrometry: 30 consecutive LASIK candidates with myopia and regular astigmatism who agree to participate in the study will have up to 4 aberrometry scans acquired consecutively using the Peramis (test) aberrometer.
    Arm Title
    Myopia (iDesign)
    Arm Type
    Active Comparator
    Arm Description
    iDesign aberrometry: The same 30 consecutive LASIK candidates scanned in the Myopia (Peramis) arm will also have up to 4 aberrometry scans acquired consecutively using the iDesign aberrometer (control) aberrometer. The order of scans (Peramis and iDesign) will be randomised.
    Arm Title
    Irregular astigmatism (Peramis)
    Arm Type
    Experimental
    Arm Description
    Peramis aberrometry: 30 consecutive cases with stage II-III keratoconus or post corneal transplantation cases with irregular astigmatism will have up to 4 aberrometry scans acquired consecutively using the Peramis (test) aberrometer
    Arm Title
    Irregular astigmatism (iDesign)
    Arm Type
    Active Comparator
    Arm Description
    iDesign aberrometry: 30 consecutive cases with stage II-III keratoconus or post corneal transplantation cases with irregular astigmatism will also have up to 4 aberrometry scans acquired consecutively using the iDesign aberrometer (control) aberrometer. The order of scans (Peramis and iDesign) will be randomised.
    Intervention Type
    Device
    Intervention Name(s)
    Peramis aberrometry
    Other Intervention Name(s)
    Wavefront scanning
    Intervention Description
    A non-invasive photographic scan sequence acquired in under 10 seconds
    Intervention Type
    Device
    Intervention Name(s)
    iDesign aberrometry
    Other Intervention Name(s)
    Wavefront scanning
    Intervention Description
    A non-invasive photographic scan sequence acquired in under 10 seconds
    Primary Outcome Measure Information:
    Title
    2nd to 4th order aberrations (5mm pupil).
    Description
    M, J0, J45, Coma, Trefoil, Spherical Aberration. Different types of defocus or aberration can be defined and measured by wavefront scanning. Aberrations are classified and quantified by a mathematical treatment called Zernike analysis in which harmonic elements of the waveform of the light detected by the wavefront sensor (aberrometer) are quantified in sequence, starting with simple (lower order) waveforms such as sphere and cylinder (M, J0, J45) corrected in a normal spectacle prescription, and progressing through more complex (higher order) waveforms including, coma, trefoil and spherical aberration which may influence quality of vision. The amount of each aberration varies as a function of pupil size. So pupil size is standardised at 5mm diameter for quantification.
    Time Frame
    <10 seconds
    Secondary Outcome Measure Information:
    Title
    % of patients with qualifying scan sequence
    Description
    % of patients in whom two 5mm diameter aberrometry scans can be acquired within 4 attempts
    Time Frame
    <5 minutes

    10. Eligibility

    Sex
    All
    Minimum Age & Unit of Time
    21 Years
    Maximum Age & Unit of Time
    60 Years
    Accepts Healthy Volunteers
    No
    Eligibility Criteria
    Inclusion Criteria: Myopic LASIK candidates (manifest refraction spherical equivalent range 0 to -10 diopters with up to 6 diopters cylinder) or patients attending corneal service with stage II-III keratoconus or post-keratoplasty Exclusion Criteria: Visually significant co-pathology (CDVA<6/6) other than irregular astigmatism; Patients unable to complete a sequence of 2 good scans (acquisition diameter >5mm) in one eye within 4 attempts
    Central Contact Person:
    First Name & Middle Initial & Last Name or Official Title & Degree
    Angelique Thomas
    Phone
    02075662156
    Email
    angelique.thomas@moorfields.nhs.uk
    First Name & Middle Initial & Last Name or Official Title & Degree
    Barbara Stacey
    Phone
    02075662320
    Email
    barbara.stacey@moorfields.nhs.uk
    Overall Study Officials:
    First Name & Middle Initial & Last Name & Degree
    Bruce Allan, MD FRCOphth
    Organizational Affiliation
    Moorfields Eye Hospital NHS Foundation Trust
    Official's Role
    Principal Investigator

    12. IPD Sharing Statement

    Plan to Share IPD
    Yes
    IPD Sharing Plan Description
    The investigators plan to publish summary descriptive data and analyses. Anonymised individual data will be available to systematic reviewers on request.
    Citations:
    PubMed Identifier
    21051697
    Citation
    Visser N, Berendschot TT, Verbakel F, Tan AN, de Brabander J, Nuijts RM. Evaluation of the comparability and repeatability of four wavefront aberrometers. Invest Ophthalmol Vis Sci. 2011 Mar 10;52(3):1302-11. doi: 10.1167/iovs.10-5841.
    Results Reference
    background
    PubMed Identifier
    19399094
    Citation
    LeDue J, Jolissaint L, Veran JP, Bradley C. Calibration and testing with real turbulence of a pyramid sensor employing static modulation. Opt Express. 2009 Apr 27;17(9):7186-95. doi: 10.1364/oe.17.007186.
    Results Reference
    background
    PubMed Identifier
    23041868
    Citation
    Cagigal MP, Valle PJ. Wavefront sensing using diffractive elements. Opt Lett. 2012 Sep 15;37(18):3813-5. doi: 10.1364/ol.37.003813.
    Results Reference
    background
    PubMed Identifier
    26046707
    Citation
    Jung JW, Chung BH, Han SH, Kim EK, Seo KY, Kim TI. Comparison of Measurements and Clinical Outcomes After Wavefront-Guided LASEK Between iDesign and WaveScan. J Refract Surg. 2015 Jun;31(6):398-405. doi: 10.3928/1081597X-20150521-06.
    Results Reference
    background

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    Measurement Repeatability in Contemporary Aberrometry

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