Comparison of Intralase and Visumax Femtosecond Laser for Laser In Situ Keratomileusis (NCT01252654) | Clinical Trial Compass
CompletedNot Applicable
Comparison of Intralase and Visumax Femtosecond Laser for Laser In Situ Keratomileusis
Singapore120 participantsStarted 2010-01
Plain-language 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.
Who can participate
Age range
21 Years – 60 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
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.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.