Measurement Repeatability in Contemporary Aberrometry

NCT02687022 | Unknown

• 1 other identifier: ALLB1019
• Study Type: interventional
• Target: 60
• Locations: 0 countries
• Sites: N/A

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.

Conditions

Refractive Errors

Outcome Measures

Primary Outcomes (1)

• 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.

  <10 seconds

Secondary Outcomes (1)

• % of patients with qualifying scan sequence

  <5 minutes

Study Arms (4)

Myopia (Peramis)

EXPERIMENTAL

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.

Device: Peramis aberrometry

Myopia (iDesign)

ACTIVE COMPARATOR

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.

Device: iDesign aberrometry

Irregular astigmatism (Peramis)

EXPERIMENTAL

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

Device: Peramis aberrometry

Irregular astigmatism (iDesign)

ACTIVE COMPARATOR

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.

Device: iDesign aberrometry

Interventions

Peramis aberrometry DEVICE

A non-invasive photographic scan sequence acquired in under 10 seconds

Also known as: Wavefront scanning

Irregular astigmatism (Peramis); Myopia (Peramis)

iDesign aberrometry DEVICE

A non-invasive photographic scan sequence acquired in under 10 seconds

Also known as: Wavefront scanning

Irregular astigmatism (iDesign); Myopia (iDesign)

Eligibility Criteria

• Age: 21 Years - 60 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Moorfields Eye Hospital NHS Foundation Trust: lead

Related Publications (4)

• 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.

  PMID: 21051697 BACKGROUND

• 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.

  PMID: 19399094 BACKGROUND

• Cagigal MP, Valle PJ. Wavefront sensing using diffractive elements. Opt Lett. 2012 Sep 15;37(18):3813-5. doi: 10.1364/ol.37.003813.

  PMID: 23041868 BACKGROUND

• 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.

  PMID: 26046707 BACKGROUND

MeSH Terms

Conditions

Refractive Errors

Condition Hierarchy (Ancestors)

Eye Diseases

Study Officials

• Bruce Allan, MD FRCOphth

  Moorfields Eye Hospital NHS Foundation Trust

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Angelique Thomas

CONTACT

02075662156; angelique.thomas@moorfields.nhs.uk

Barbara Stacey

CONTACT

02075662320; barbara.stacey@moorfields.nhs.uk

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: INVESTIGATOR
• Purpose: DIAGNOSTIC
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Consultant Ophthalmic Surgeon

Study Record Dates

• First Submitted: February 7, 2016
• First Posted: February 22, 2016
• Study Start: March 1, 2016
• Primary Completion: June 1, 2016
• Study Completion: September 1, 2016
• Last Updated: February 22, 2016

Record last verified: 2016-02

Data Sharing

• IPD Sharing: Will share