KeratoconusT-CatNCT00777322
T-Cat Laser & Cross-linking for Keratoconus
A study testing Excimer laser ablation, and collagen cross-linking in people with Keratoconus and Pellucid Marginal Degeneration, run by Moorfields Eye Hospital NHS Foundation Trust at 1 site in United Kingdom.
Trial summary
The purpose of this study is to determine whether excimer laser corneal surface ablation (T-Cat) can be safely combined with simultaneous corneal collagen cross-linking treatment to produce an improved and stable corneal profile in the treatment of keratoconus. Read more about this study
- Who is it for?
- Ages 18 to 50 years
- Conditions the study is for
- Keratoconus, Pellucid Marginal Degeneration
- What is being tested?
- Excimer laser ablation, and collagen cross-linking
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 15 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Oct 2008to Oct 2010
- 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 18 to 50 years
- All sexes
- No healthy volunteers
- Adult
Who may be able to join
- Patients with known keratoconus or pellucid marginal degeneration.
Who cannot join
- Age < 18 years > 50 years.
- Minimal corneal pachymetry in eye to be treated of < 400μ.
- Evidence of other corneal disease in the eye to be treated (e.g. Herpes simplex keratitis).
- Women who are pregnant or nursing at the time of the initial treatment.
- Presence of significant central corneal opacity.
- Patients unwilling to not wear rigid contact lenses in the eye to be operated on for at least one month before baseline examination, and for the first six months post-operatively.
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Moorfields Eye Department at St George's Hospital
London, London, SW17 0QT
About this study
Official title: Pilot Study of Excimer Laser Topography-Computer Assisted Treatment (T-Cat) Combined With Corneal Collagen Cross-linking With Riboflavin and UV Light
The purpose of this study is to determine whether excimer laser corneal surface ablation (T-Cat) can be safely combined with simultaneous corneal collagen cross-linking treatment to produce an improved and stable corneal profile in the treatment of keratoconus.
Read the detailed description
Theoretical framework:
Corneal ectasia is a relative weakness in the structure of the cornea, which produces a progressive change in its shape with resultant visual distortion.
Excimer laser surface ablation can be used to re-shape the corneal profile. When the corneal shape is very irregular, corneal topography data gives the best information as to how to re-shape the cornea into a normal profile, and this Topography-Computer Assisted Treatment (T-Cat) will be used to modulate the surface corneal shape.
It is known that collagen cross-linking in the cornea occurs naturally with age, and in diabetes, both of which seem to prevent progressive ectasia. Corneal collagen cross-linking with riboflavin has been shown to stabilize the cornea in keratoconus, and prevents progression of the disease. If cross-linking is performed at that moment that the cornea has been re-shaped by T-Cat treatment, it should help prevent the corneal thinning resultant from the laser treatment from destabilising the cornea and causing progressive ectasia.
Purpose:
To determine whether excimer laser corneal surface ablation (T-Cat) can be safely combined with simultaneous corneal collagen cross-linking treatment to produce an improved and stable corneal profile.
Design:
Prospective, interventional trial.
- Conditions
- Keratoconus, Pellucid Marginal Degeneration
- Being tested
- Excimer laser ablation, and collagen cross-linking
- Keywords
- keratoconus, pellucid marginal degeneration, corneal ectasia, collagen cross-linking, riboflavin, UV light, excimer laser, Topography-Computer Assisted Treatment (T-Cat), Wavelight Allegretto laser
- Medical subject headings
- Keratoconus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Excimer laser ablation, and collagen cross-linkingProcedure or surgery
Also called Ricrolin (riboflavin 0.1% in dextran), Pecshke UV-X illumination system
Surgery is performed with topical anaesthesia. The central corneal epithelium is removed. Excimer laser ablation is applied (typically 15-30 seconds). Residual bed thickness is checked with an ultrasonic pachymeter. Topical application of riboflavin 0.1% in dextran is commenced at 5 minute intervals. When an adequate saturation of the anterior chamber with riboflavin has been achieved, cross-linking treatment will proceed. Output from the UV light generating equipment is measured with a UV light meter and set at 3mW/cm². Thirty minutes of treatment is given, interrupted at five minute intervals by the application of more topical riboflavin drops. Finally the eye has a bandage soft contact lens placed, with preservative free topical antibiotic, steroid, and cycloplegic drop application.
| Study group | Role | What they receive |
|---|---|---|
| Interventional study | Experimental | Patients with known keratoconus or pellucid marginal degeneration will be invited to join the study. The study is partly a continuation in the management of patients who have had previous keratophakia, who will have near-normal or supra-physiological levels of corneal thickness. It is also intended for patients with relatively mild keratoconus who have sufficient corneal thickness to allow a limited laser ablation whilst still leaving a residual stromal bed of at least 350μ. Receives: Procedure: Excimer laser ablation, and collagen cross-linking |
What is being measured
The primary outcome is the main question the study is designed to answer.
The difference in the pre- and post-operative unaided visual acuity, best corrected visual acuity, and refraction.
Measured: At six months
Secondary outcomes (1)
Corneal topographic profile.
Measured: At six months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Oct 2008 (estimated)
- Study startOct 2008
- Primary completionOct 2010
- Study completionOct 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for KeratoconusStudies of the same condition, open and under way.
- 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
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 15 participants (actual)
Sponsor and investigators
- Lead sponsor
- Moorfields Eye Hospital NHS Foundation Trust
- Sponsor type
- University, hospital or other
- Collaborators
- Accuvision Laser Eye Clinics, Carleton Optical Equipment Ltd., Bon Optics, Sooft Italia
- Investigators
- Chad K Rostron, MB BS, Principal investigator, Moorfields Eye Hospital NHS Foundation Trust
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00777322
- Sponsor's protocol ID
- REC Ref: 07/H0721/94
- Acronym
- T-Cat
- Status last verified
- Apr 2009
- First submitted
- 21 Oct 2008
- Last updated
- 21 Jul 2011
- Results posted
- No
- Data monitoring committee
- Yes
Study at a glance
From the registry record, last updated by the sponsor on 21 Jul 2011. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pilot Study of Excimer Laser Topography-Computer Assisted Treatment (T-Cat) Combined With Corneal Collagen Cross-linking With Riboflavin and UV Light
- ClinicalTrials.gov ID
- NCT00777322
- Acronym / sponsor ID
- T-Cat / REC Ref: 07/H0721/94
- Conditions
- Keratoconus, Pellucid Marginal Degeneration
- Keywords
- keratoconus, pellucid marginal degeneration, corneal ectasia, collagen cross-linking, riboflavin, UV light, excimer laser, Topography-Computer Assisted Treatment (T-Cat)
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 15 participants (actual)
- Lead sponsor
- Moorfields Eye Hospital NHS Foundation TrustUniversity, hospital or other
- Collaborators
- Accuvision Laser Eye Clinics, Carleton Optical Equipment Ltd., Bon Optics, Sooft Italia
- Study start
- Oct 2008
- Primary completion
- Oct 2010 (actual)
- Study completion
- Oct 2010 (actual)
- First posted
- 22 Oct 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.
The purpose of this study is to determine whether excimer laser corneal surface ablation (T-Cat) can be safely combined with simultaneous corneal collagen cross-linking treatment to produce an improved and stable corneal profile in the treatment of keratoconus.
Detailed description
Theoretical framework:
Corneal ectasia is a relative weakness in the structure of the cornea, which produces a progressive change in its shape with resultant visual distortion.
Excimer laser surface ablation can be used to re-shape the corneal profile. When the corneal shape is very irregular, corneal topography data gives the best information as to how to re-shape the cornea into a normal profile, and this Topography-Computer Assisted Treatment (T-Cat) will be used to modulate the surface corneal shape.
It is known that collagen cross-linking in the cornea occurs naturally with age, and in diabetes, both of which seem to prevent progressive ectasia. Corneal collagen cross-linking with riboflavin has been shown to stabilize the cornea in keratoconus, and prevents progression of the disease. If cross-linking is performed at that moment that the cornea has been re-shaped by T-Cat treatment, it should help prevent the corneal thinning resultant from the laser treatment from destabilising the cornea and causing progressive ectasia.
Purpose:
To determine whether excimer laser corneal surface ablation (T-Cat) can be safely combined with simultaneous corneal collagen cross-linking treatment to produce an improved and stable corneal profile.
Design:
Prospective, interventional trial.
Study design
- Primary purpose
- Treatment
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Interventional study | Experimental | Procedure: Excimer laser ablation, and collagen cross-linkingPatients with known keratoconus or pellucid marginal degeneration will be invited to join the study. The study is partly a continuation in the management of patients who have had previous keratophakia, who will have near-normal or supra-physiological levels of corneal thickness. It is also intended for patients with relatively mild keratoconus who have sufficient corneal thickness to allow a limited laser ablation whilst still leaving a residual stromal bed of at least 350μ. |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (1 listed)
- Patients with known keratoconus or pellucid marginal degeneration.
Key exclusion criteria (6 listed)
- Age < 18 years > 50 years.
- Minimal corneal pachymetry in eye to be treated of < 400μ.
- Evidence of other corneal disease in the eye to be treated (e.g. Herpes simplex keratitis).
- Women who are pregnant or nursing at the time of the initial treatment.
- Presence of significant central corneal opacity.
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 |
|---|---|---|
| Excimer laser ablation, and collagen cross-linkingAlso: Ricrolin (riboflavin 0.1% in dextran), Pecshke UV-X illumination systemSurgery is performed with topical anaesthesia. The central corneal epithelium is removed. Excimer laser ablation is applied (typically 15-30 seconds). Residual bed thickness is checked with an ultrasonic pachymeter. Topical application of riboflavin 0.1% in dextran is commenced at 5 minute intervals. When an adequate saturation of the anterior chamber with riboflavin has been achieved, cross-linking treatment will proceed. Output from the UV light generating equipment is measured with a UV light meter and set at 3mW/cm². Thirty minutes of treatment is given, interrupted at five minute intervals by the application of more topical riboflavin drops. Finally the eye has a bandage soft contact lens placed, with preservative free topical antibiotic, steroid, and cycloplegic drop application. | Procedure or surgery | Interventional study |
Primary outcome
The difference in the pre- and post-operative unaided visual acuity, best corrected visual acuity, and refraction.
Time frame: At six months
1 secondary outcome
Corneal topographic profile.
Time frame: At six months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Jul 2011.
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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.
Chad K Rostron, MB BS principal investigator
Moorfields Eye Hospital NHS Foundation Trust
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Excimer laser ablation, and collagen cross-linking in people with Keratoconus and Pellucid Marginal Degeneration, run by Moorfields Eye Hospital NHS Foundation Trust at 1 site in United Kingdom.
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 1 inclusion and 6 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: finished, as of the sponsor's last update on 21 Jul 2011. 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 Kingdom. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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?
The difference in the pre- and post-operative unaided visual acuity, best corrected visual acuity, and refraction. (time frame: At six months). 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 21 Jul 2011; AzTrials last refreshed its copy on 31 Oct 2026.