MyopiaIDESNCT00803478
The Effect of Hinge Position and Hinge Width on Corneal Sensation and Dry Eye After IntraLase LASIK Procedure
A study testing LASIK in people with Myopia, run by University of Michigan at 1 site in United States.
Trial summary
Corneal sensation is known to play a role in tear secretion. Decreased sensation leads to decreased tear production; and when bilateral, leads to a decreased blink rate as well. Dry eyes are a common side effect of LASIK. Incidence rates vary widely, but have been reported in as many as 59% of patients. Read more about this study
- Who is it for?
- Ages 20 to 70 years
- Conditions the study is for
- Myopia
- What is being tested?
- LASIK
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 0 participants
- Where
- 1 siteUnited States
- Study dates
- Jun 2004to Dec 2015
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 70 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Refractive error: Myopia < 12 D, with astigmatism < 3 D,
- Age > 20 y/o
- Regular corneal curvature, sufficient corneal thickness, appropriate pupil size, normal slit lamp examination
- Informed consent to permit us to use their records for this study without using name, medical record number, or date of surgery.
Who cannot join
- Pregnant/nursing
- Systemic collagen vascular disease
- Autoimmune disease
- Severe dry eyes
Trial locations and contacts
1 site in 1 country.
United States1 site
Cornea Clinic, Kellogg Eye Center
Ann Arbor, Michigan, 48105
About this study
Corneal sensation is known to play a role in tear secretion. Decreased sensation leads to decreased tear production; and when bilateral, leads to a decreased blink rate as well. Dry eyes are a common side effect of LASIK. Incidence rates vary widely, but have been reported in as many as 59% of patients. And almost all patients have some transient dry eye symptoms immediately following LASIK.
Previous studies have looked at the effect of hinge position (superior vs. nasal) and hinge width on corneal sensation and dry eye after LASIK performed with a mechanical microkeratome. Corneal sensation was decreased and dry eye signs and symptoms increased immediately following LASIK in all eyes. These parameters then improved at all time periods between 1 week and 6 months post-operative. Loss of corneal sensation and dry eye signs and symptoms were greater in eyes with superior-hinge flap than nasal-hinge flap, and in eyes with narrower hinge flap rather than wider hinge flap IntraLase LASIK, using the IntraLase femtosecond laser rather than a mechanical microkeratome to cut the corneal flap, has become an increasingly popular procedure. It provides several advantages over mechanical microkeratomes, including reduced surgical complications, more predictable flap thickness, better astigmatic neutrality, decreased epithelial injury, and an ability to operate on a wider range of patients.
The investigators propose this study to evaluate the effect of flap hinge size and flap thickness in corneal flaps created with the IntraLase laser. The investigators would like to determine if there is a difference from the previously discussed results found when using the mechanical microkeratome. Also, with the increased ease of programming alternate hinge width or flap thickness with IntraLase, if the investigators find a significant difference with an alternate flap configuration, it might translate to a feasible change in clinical practice.
Read the detailed description
Corneal innervation/sensation is supplied by the long ciliary nerves which branch from the trigeminal nerve. The nerves enter the cornea in the mid-stroma at the nasal and temporal limbus. They then branch and turn anterior to form a dense plexus sub-Bowman's layer. The nerves finally terminate in the wing cell layer from where they enervate the epithelium. Corneal sensation has been shown to be decreased after all corneal surgeries, including LASIK.
Corneal sensation is known to play a role in tear secretion. Decreased sensation leads to decreased tear production; and when bilateral, leads to a decreased blink rate as well. Dry eyes are a common side effect of LASIK. Incidence rates vary widely, but have been reported in as many as 59% of patients. And almost all patients have some transient dry eye symptoms immediately following LASIK.
Previous studies have looked at the effect of hinge position (superior vs. nasal) and hinge width on corneal sensation and dry eye after LASIK performed with a mechanical microkeratome.1,2 Corneal sensation was decreased and dry eye signs and symptoms increased immediately following LASIK in all eyes. These parameters then improved at all time periods between 1 week and 6 months post-operative. Loss of corneal sensation and dry eye signs and symptoms were greater in eyes with superior-hinge flap than nasal-hinge flap, and in eyes with narrower hinge flap rather than wider hinge flap IntraLase LASIK, using the IntraLase femtosecond laser rather than a mechanical microkeratome to cut the corneal flap, has become an increasingly popular procedure. It provides several advantages over mechanical microkeratomes, including reduced surgical complications, more predictable flap thickness, better astigmatic neutrality, decreased epithelial injury,3 and an ability to operate on a wider range of patients.
We propose this study to evaluate the effect of flap hinge position and size in corneal flaps created with the IntraLase laser. We would like to determine if there is a difference from the previously discussed results found when using the mechanical microkeratome. Also, with the increased ease of programming alternate hinge position and width with IntraLase, if we find a significant difference with an alternate flap configuration, it might translate to a feasible change in clinical practice.
Specific Aims: To evaluate the effect of hinge position (superior vs. temporal) , hinge width (45 vs. 90 degrees), and flap thickness on corneal sensation and dry eye after IntraLase LASIK.
- Conditions
- Myopia
- Being tested
- LASIK
- Keywords
- IntraLase LASIK for primary myopia
- Medical subject headings
- Myopia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
LASIKProcedure or surgery
| Study group | Role | What they receive |
|---|---|---|
| Hinge position | Active comparator | superior vs. temporal Receives: Procedure: LASIK |
| Hinge width | Active comparator | 45 vs 90 degrees Receives: Procedure: LASIK |
| Flap Thickness | Active comparator | 110 vs 130 microns Receives: Procedure: LASIK |
What is being measured
The primary outcome is the main question the study is designed to answer.
To evaluate the effect of hinge position (superior vs. temporal) , hinge width (45 vs. 90 degrees), and flap thickness on corneal sensation and dry eye after IntraLase LASIK.
Measured: pre operative and 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months post-operative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Dec 2008 (estimated)
- Study startJun 2004
- Primary completionSep 2008
- Study completionDec 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for MyopiaStudies of the same condition, open and under way.
- More trials run by University of MichiganThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Michigan
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Shahzad Mian, University of Michigan
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00803478
- Sponsor's protocol ID
- HUM 18730-IDES
- Acronym
- IDES
- Status last verified
- Feb 2016
- First submitted
- 4 Dec 2008
- Last updated
- 3 Feb 2016
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Feb 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Hinge Position and Hinge Width on Corneal Sensation and Dry Eye After IntraLase LASIK Procedure
- ClinicalTrials.gov ID
- NCT00803478
- Acronym / sponsor ID
- IDES / HUM 18730-IDES
- Conditions
- Myopia
- Keywords
- IntraLase LASIK for primary myopia
- Study type
- Interventional
- Recruitment status
- Withdrawn
- Enrolment
- 0 participants (actual)
- Lead sponsor
- University of MichiganUniversity, hospital or other
- Study start
- Jun 2004
- Primary completion
- Sep 2008 (actual)
- Study completion
- Dec 2015 (actual)
- First posted
- 5 Dec 2008 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Corneal sensation is known to play a role in tear secretion. Decreased sensation leads to decreased tear production; and when bilateral, leads to a decreased blink rate as well. Dry eyes are a common side effect of LASIK. Incidence rates vary widely, but have been reported in as many as 59% of patients. And almost all patients have some transient dry eye symptoms immediately following LASIK.
Previous studies have looked at the effect of hinge position (superior vs. nasal) and hinge width on corneal sensation and dry eye after LASIK performed with a mechanical microkeratome. Corneal sensation was decreased and dry eye signs and symptoms increased immediately following LASIK in all eyes. These parameters then improved at all time periods between 1 week and 6 months post-operative. Loss of corneal sensation and dry eye signs and symptoms were greater in eyes with superior-hinge flap than nasal-hinge flap, and in eyes with narrower hinge flap rather than wider hinge flap IntraLase LASIK, using the IntraLase femtosecond laser rather than a mechanical microkeratome to cut the corneal flap, has become an increasingly popular procedure. It provides several advantages over mechanical microkeratomes, including reduced surgical complications, more predictable flap thickness, better astigmatic neutrality, decreased epithelial injury, and an ability to operate on a wider range of patients.
The investigators propose this study to evaluate the effect of flap hinge size and flap thickness in corneal flaps created with the IntraLase laser. The investigators would like to determine if there is a difference from the previously discussed results found when using the mechanical microkeratome. Also, with the increased ease of programming alternate hinge width or flap thickness with IntraLase, if the investigators find a significant difference with an alternate flap configuration, it might translate to a feasible change in clinical practice.
Detailed description
Corneal innervation/sensation is supplied by the long ciliary nerves which branch from the trigeminal nerve. The nerves enter the cornea in the mid-stroma at the nasal and temporal limbus. They then branch and turn anterior to form a dense plexus sub-Bowman's layer. The nerves finally terminate in the wing cell layer from where they enervate the epithelium. Corneal sensation has been shown to be decreased after all corneal surgeries, including LASIK.
Corneal sensation is known to play a role in tear secretion. Decreased sensation leads to decreased tear production; and when bilateral, leads to a decreased blink rate as well. Dry eyes are a common side effect of LASIK. Incidence rates vary widely, but have been reported in as many as 59% of patients. And almost all patients have some transient dry eye symptoms immediately following LASIK.
Previous studies have looked at the effect of hinge position (superior vs. nasal) and hinge width on corneal sensation and dry eye after LASIK performed with a mechanical microkeratome.1,2 Corneal sensation was decreased and dry eye signs and symptoms increased immediately following LASIK in all eyes. These parameters then improved at all time periods between 1 week and 6 months post-operative. Loss of corneal sensation and dry eye signs and symptoms were greater in eyes with superior-hinge flap than nasal-hinge flap, and in eyes with narrower hinge flap rather than wider hinge flap IntraLase LASIK, using the IntraLase femtosecond laser rather than a mechanical microkeratome to cut the corneal flap, has become an increasingly popular procedure. It provides several advantages over mechanical microkeratomes, including reduced surgical complications, more predictable flap thickness, better astigmatic neutrality, decreased epithelial injury,3 and an ability to operate on a wider range of patients.
We propose this study to evaluate the effect of flap hinge position and size in corneal flaps created with the IntraLase laser. We would like to determine if there is a difference from the previously discussed results found when using the mechanical microkeratome. Also, with the increased ease of programming alternate hinge position and width with IntraLase, if we find a significant difference with an alternate flap configuration, it might translate to a feasible change in clinical practice.
Specific Aims: To evaluate the effect of hinge position (superior vs. temporal) , hinge width (45 vs. 90 degrees), and flap thickness on corneal sensation and dry eye after IntraLase LASIK.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| Hinge position | Active comparator | Procedure: LASIKsuperior vs. temporal |
| Hinge width | Active comparator | Procedure: LASIK45 vs 90 degrees |
| Flap Thickness | Active comparator | Procedure: LASIK110 vs 130 microns |
Who may qualify
- Ages
- 20 to 70 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Refractive error: Myopia < 12 D, with astigmatism < 3 D,
- Age > 20 y/o
- Regular corneal curvature, sufficient corneal thickness, appropriate pupil size, normal slit lamp examination
- Informed consent to permit us to use their records for this study without using name, medical record number, or date of surgery.
Key exclusion criteria (4 listed)
- Pregnant/nursing
- Systemic collagen vascular disease
- Autoimmune disease
- Severe dry eyes
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| LASIK | Procedure or surgery | Flap Thickness, Hinge position, Hinge width |
Primary outcome
To evaluate the effect of hinge position (superior vs. temporal) , hinge width (45 vs. 90 degrees), and flap thickness on corneal sensation and dry eye after IntraLase LASIK.
Time frame: pre operative and 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months post-operative
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Feb 2016.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing LASIK in people with Myopia, run by University of Michigan at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: withdrawn, as of the sponsor's last update on 3 Feb 2016. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was withdrawn before enrolling participants, so there are no results.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To evaluate the effect of hinge position (superior vs. temporal) , hinge width (45 vs. 90 degrees), and flap thickness on corneal sensation and dry eye after IntraLase LASIK. (time frame: pre operative and 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months post-operative). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Feb 2016.