Comparison of Intralase and Visumax Femtosecond Laser for Laser In Situ Keratomileusis

The recruitment status of this study is unknown because the information has not been verified recently.
Verified May 2010 by Singapore Eye Research Institute.
Recruitment status was  Recruiting
Sponsor:
Information provided by:
Singapore Eye Research Institute
ClinicalTrials.gov Identifier:
NCT01252654
First received: May 10, 2010
Last updated: December 1, 2010
Last verified: May 2010
  Purpose

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.


Condition
Myopia

Study Type: Observational
Study Design: Observational Model: Case Control
Time Perspective: Prospective

Further study details as provided by Singapore Eye Research Institute:

Primary Outcome Measures:
  • Visual Acuity [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • complications [ Time Frame: 3 months ] [ Designated as safety issue: Yes ]
  • Subjective questionnaire [ Time Frame: 1 weekd ] [ Designated as safety issue: No ]
  • Corneal Sensation [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  • Tear function [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  • Wavefront analysis [ Time Frame: 3 months ] [ Designated as safety issue: No ]
  • Contrast Sensitivity [ Time Frame: 3 months ] [ Designated as safety issue: No ]

Estimated Enrollment: 45
Study Start Date: January 2010
Estimated Study Completion Date: December 2010
Estimated Primary Completion Date: August 2010 (Final data collection date for primary outcome measure)
Groups/Cohorts
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

Ages Eligible for Study:   21 Years to 60 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Myopic patients presenting to refractive service eligible for LASIK

Criteria

Inclusion Criteria:

  • 21 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.

Exclusion Criteria:

  • 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.
  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: NCT01252654

Contacts
Contact: Donald Tan, MD, FRCS 6322 4533 snecdt@pacific.net.sg
Contact: Jod Mehta, MD FRCS 6322 4533 jodmehta@gmail.com

Locations
Singapore
Singapore National Eye Centre Recruiting
Singapore, Singapore, 168751
Contact: Donald Tan       snecdt@pacific.net.sg   
Contact: Jod Mehta       jodmehta@gmail.com   
Sub-Investigator: Jod Mehta         
Sponsors and Collaborators
Singapore Eye Research Institute
Investigators
Principal Investigator: Donald Tan Singapore National Eye Centre
  More Information

No publications provided

Responsible Party: Professor D Tan, Singapore National Eye Centre / SIngapore Eye Research Institute
ClinicalTrials.gov Identifier: NCT01252654     History of Changes
Other Study ID Numbers: R683/33/2009, Other
Study First Received: May 10, 2010
Last Updated: December 1, 2010
Health Authority: Singapore: Singhealth Centralised IRB

Keywords provided by Singapore Eye Research Institute:
Lasik
Femtosecond Laser
Visumax
IntraLase
Myopia
Myopic Patients undergoing LASIK

Additional relevant MeSH terms:
Myopia
Refractive Errors
Eye Diseases

ClinicalTrials.gov processed this record on September 11, 2014