NCT01252654

Brief Summary

Emtosecond lasers are used in cutting the flap in LASIK procedures (laser corrective surgery for refractive error). Their use has decreased the incidence of serious complications when compared to the use of microkeratomes(mechanical blades). The commonest femtosecond laser currently used is 'Intralase'. A newer femtosecond laser 'Visumax' (Zeiss) is now available and differs from the Intralase in that it does not interfere with the curvature of the cornea when creating the flap. The Intralase applanates the cornea flat during flap creation which causes the intraocular pressure to be higher. Both Intralase and Visumax lasers are available to patients and surgeons to use at SNEC. The aim of the investigators study is to compare the two lasers in a randomization of left and right eyes in the same patient. The investigators want to measure any difference that the lower intraocular pressure may have during the creation of the flap. This will be measured with a questionaire on patient experience during the procedure and the outcomes of vision, refraction, contrast sensitivity, wave-front analysis, tear function,corneal sensation and flap thickness measured with anterior segment OCT during the post-operative follow up period. To date no-one has compared the use of these two femtosecond lasers. Both lasers are currently used clinically for flap creation at SNEC.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
120

participants targeted

Target at P50-P75 for all trials

Timeline
Completed

Started Jan 2010

Typical duration for all trials

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

January 1, 2010

Completed
4 months until next milestone

First Submitted

Initial submission to the registry

May 10, 2010

Completed
7 months until next milestone

First Posted

Study publicly available on registry

December 3, 2010

Completed
1.7 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 1, 2012

Completed
1 year until next milestone

Study Completion

Last participant's last visit for all outcomes

August 1, 2013

Completed
Last Updated

April 24, 2026

Status Verified

July 1, 2016

Enrollment Period

2.6 years

First QC Date

May 10, 2010

Last Update Submit

April 22, 2026

Conditions

Myopia

Keywords

LasikFemtosecond LaserVisumaxIntraLaseMyopiaMyopic Patients undergoing LASIK

Outcome Measures

Primary Outcomes (1)

  • Visual Acuity

    3 months

Secondary Outcomes (6)

  • complications

    3 months

  • Subjective questionnaire

    1 weekd

  • Corneal Sensation

    3 months

  • Tear function

    3 months

  • Wavefront analysis

    3 months

  • +1 more secondary outcomes

Study Arms (2)

1 IntraLase flaps

Patients who have undergone flap creation with IntraLase laser

2 Visumax flaps

Patients who have undergone flaps created with Visumax laser

Eligibility Criteria

Age21 Years - 60 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64)
Sampling MethodNon-Probability Sample
Study Population

Myopic patients presenting to refractive service eligible for LASIK

You may qualify if:

  • years of age or older.
  • Cycloplegic spherical equivalent of \>-1.00D
  • Refractive cylinder -4.00 D or less.
  • Best spectacle corrected visual acuity (BSCVA) of 6/12 or better in BOTH eyes.
  • Spherical or cylindrical error has progressed at -0.50D or less per year from date of baseline measurement.
  • Contact lens wearers must have removed contact lenses at least two (2) weeks before the baseline measurement.
  • No evidence of irregular astigmatism on corneal topography.
  • Available to attend post-operative examinations for a 3 month period.

You may not qualify if:

  • Progressive or unstable myopia and/or astigmatism.
  • Clinical or corneal topographic evidence of keratoconus.
  • Residual, recurrent or active ocular disease such as uveitis, severe dry eyes, severe allergic eye disease, glaucoma, visually significant cataract and retinal disease.
  • Previous corneal surgery or trauma within the corneal flap zone.
  • Patent corneal vascularization within 1mm of the corneal flap zone.
  • Taking systemic medications likely to affect wound healing, such as corticosteroids and antimetabolites.
  • Systemically immunocompromised.
  • Systemic disease likely to affect wound healing, such as diabetes, connective tissue disease and severe atopy.
  • Pregnant or nursing.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Singapore National Eye Centre

Singapore, 168751, Singapore

Location

Related Publications (1)

  • D'Souza S, Petznick A, Tong L, Hall RC, Rosman M, Chan C, Koh SK, Beuerman RW, Zhou L, Mehta JS. Comparative analysis of two femtosecond LASIK platforms using iTRAQ quantitative proteomics. Invest Ophthalmol Vis Sci. 2014 May 6;55(6):3396-402. doi: 10.1167/iovs.14-14113.

    PMID: 24801511DERIVED

MeSH Terms

Conditions

Myopia

Condition Hierarchy (Ancestors)

Refractive ErrorsEye Diseases

Study Officials

  • Donald Tan

    Singapore National Eye Centre

    PRINCIPAL INVESTIGATOR

Study Design

Study Type
observational
Observational Model
CASE CONTROL
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Head Tissue Engineering and Stem Cell Group

Study Record Dates

First Submitted

May 10, 2010

First Posted

December 3, 2010

Study Start

January 1, 2010

Primary Completion

August 1, 2012

Study Completion

August 1, 2013

Last Updated

April 24, 2026

Record last verified: 2016-07

Locations

SG(1)