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Corneal Melting in Boston Keratoprosthesis Type ICXL-KProNCT03041883

Corneal Collagen Crosslinking to Increase the Resistance of the Support Graft of the KPro Type I Against Corneal Melting

A study testing Crosslinking with riboflavin of the corneal graft-support and De-epithelisation of the corneal graft support with instillation of riboflavin in people with Corneal Melting in Boston Keratoprosthesis Type I, run by Centre hospitalier de l'Université de Montréal (CHUM) at 1 site in Canada.

Recruiting

Looking for participants now. Contact the study team or a site below to ask about taking part.

Sites and contacts
Official record
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Trial summary

The purpose of this study is to demonstrate the safety and efficacy of the corneal collagen crosslinking with riboflavin and ultraviolet A in aim to increase the resistance of the graft used as a support for the Boston keratoprosthesis (KPro) type I against corneal melting (keratolysis or sterile necrosis). Read more about this study

Who is it for?
Ages 18 to 80 years
What is being tested?
Crosslinking with riboflavin of the corneal graft-support and De-epithelisation of the corneal graft support with instillation of riboflavin
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
40 participants
Where
1 siteCanada
Study dates
4 Jan 2017to Jan 2028
Phase
Interventional
Are there results?
Not yet: the study is under way

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 80 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Candidate for KPro type I
  • Capacity to give written consent
  • Ability to be followed for the duration of the study

Who cannot join

  • Participation in another interventional study
  • Failure to wear a therapeutic contact lens due to abnormalities of the eyelids.
  • Inability to give written consent
  • Contraindications to the KPro type I:
  • Severe dryness with keratinization of the ocular surface
  • Intraocular tumor
Show all 9Show fewer
  • Terminal glaucoma
  • Inoperable retinal detachment
  • Phthisis bulbi

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Canada1 site, 1 recruiting
  • Centre Hospitalier de l'Université de Montréal

    Montreal, Quebec, H2X3E4

    Marie-Catherine Tessier, 514 890-8000 ext. 11550, marie-catherine.tessier.chum@ssss.gouv.qc.ca

    Recruiting

Other trials in Canada

About this study

Official title: Corneal Collagen Crosslinking to Increase the Resistance of the Graft Used as a Support for the Boston Keratoprosthesis Type I Against Corneal Melting

The purpose of this study is to demonstrate the safety and efficacy of the corneal collagen crosslinking with riboflavin and ultraviolet A in aim to increase the resistance of the graft used as a support for the Boston keratoprosthesis (KPro) type I against corneal melting (keratolysis or sterile necrosis).

Read the detailed description

The Boston type 1 keratoprosthesis (KPro) is an artificial cornea that restores the clarity of the visual axis. It is indicated in patients for whom conventional corneal transplantation offers a very low probability of success. Several innovations have led to improved outcomes following implantation of a KPro. However, retention of the KPro varies between 83 and 100% in the most recent series. The extrusion of the KPro is usually caused by the melting of the corneal tissue (keratolysis or sterile necrosis) used as a support.

This corneal melting is mediated by enzymes from the class of the matrix metalloproteinases (MMP). Several different types of insults may lead to an excess of these enzymes. Chronic inflammation of the ocular surface is undoubtedly the best recognized risk factor. Indeed, autoimmune diseases such as Stevens-Johnson syndrome, Lyell syndrome (toxic epidermal necrolysis, TENS) and mucous membrane pemphigoid, has the highest rate of corneal melting post KPro. Moreover, the development of a retroprosthetic membrane has recently been recognized as a risk factor for melting. Furthermore, the dryness of the corneal epithelium, due to insufficient tear production or an alteration of the blink reflex of the eye, can also lead to an overexpression of MMP. Finally, infectious keratitis can lead to significant thinning of the corneal tissue, even once the infectious process is resolved.

Corneal collagen cross-linking is a technique approved by Health Canada for strengthening the biomechanical properties of the cornea. The crosslinked corneas become more resistant to collagenase and other MMP. The use of a crosslinked corneal graft as a support for the KPro is an interesting approach to the prevention of corneal melting.

A prospective, randomized, controlled and double-blind study will be conducted with patients receiving a Kpro at the Centre Hospitalier de l'Université de Montréal. Forty patients will be randomized into two groups, half will receive KPro in a crosslinked graft-support, while the other half will receive a usual graft-support. Patients will be met by their surgeon to discuss the risks, benefits of the KPro type I and alternatives treatments. Patients accepting KPro surgery, will be informed of the nature and course of the study and will be offered to participate in the study. The Eye bank of Canada will manage the randomization and maintain the codes identifying the crosslinked corneas from the untreated corneas, keeping both the surgeon and the patient blinded. Randomization will be done through a free application (http://www.randomizer.org/form.htm). A series of 10 numbers will be generated. Even numbers indicate crosslinked corneas and odd numbers indicate non-crosslinked corneas. The order of the digits will increase as for each subject is enrolled in the study. The procedure for corneal collagen crosslinking will be performed at the Eye Bank of Canada in a similar procedure to the treatment for keratoconus. Under sterile conditions, the corneo-scleral button will be inspected to meet the standard of care. If the patient is randomized to the crosslinked group, then the cornea will be treated with crosslinking as described further. If the patient is randomized the control group, the cornea will not be treated with crosslink but will be deepithelialized and soaked with riboflavin drops as described further.

The surgeon will receive the graft and operate according to the standard procedure. The KPro surgery and postoperative care will be performed in the standard way and thus will be the same for both study groups. Postoperative follow will be held at 1 day, 1 week, 2 weeks, 1 month and 3 months and will continue subsequently every 2-4 months depending on the judgment of the surgeon. These visits will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination. In particular, the presence of corneal melting, leakage of aqueous humor, corneal infection and extrusion will be noted. Meanwhile, an imaging allowing quantification of the thickness of the cornea graft-support (optical coherence tomography anterior segment) will be performed at least once during the first three months postoperative. This imaging will be repeated at 1, 2 and 5 years.

The prevalence of various complications (melting, leak, infection, extrusion) will be compared between the two groups with the Fischer exact test. Also, the time between surgery and the occurrence of complications will be compared using the Student t test. Finally, survival analysis of Kaplan-Meier will be performed for 1) the occurrence of corneal melting and 2) maintaining a visual acuity greater than 20/200.

Being tested
Crosslinking with riboflavin of the corneal graft-support, De-epithelisation of the corneal graft support with instillation of riboflavin

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Crosslinking with riboflavin of the corneal graft-supportProcedure or surgery

    Corneal graft support for the KPro will be crosslinked and used with the standard surgical technique

  • De-epithelisation of the corneal graft support with instillation of riboflavinProcedure or surgery

    Corneal graft-support will be de-epithelialized and soaked with riboflavin and then used with the standard surgical technique

Study groups in NCT03041883
Study groupRoleWhat they receive
Kpro with crosslinked graft-supportExperimentalPatient will receive a crosslinked corneal graft-support for the KPro type I. Under sterile conditions, the corneo-scleral button will be inspected, then placed on an artificial anterior chamber. The epithelium of the donor will be removed mechanically. Then one drop of riboflavin 0.1%/dextran 20% will be applied to 3 minutes on the de-epithelialized cornea for 15 minutes. Then, the source of ultraviolet A (UVA) will be irradiating the cornea for 30 minutes with a wavelength of 370 nanometer(nm) length with 5.4 joules(J)/ square centimeter (cm2) and 3 milliwatts(mW)/cm2. Meanwhile, the instillation of a drop of 0.1% riboflavin/dextran 20% continues every 5 minutes. Goggles against UVA are mandatory. The crosslinked graft-support will be forwarded to the surgeon according to standard procedure.
Receives: Procedure: Crosslinking with riboflavin of the corneal graft-support
KPro with normal graft-supportActive comparatorPatient wil receive a normal graft-support for the KPro type I. Under sterile conditions, the corneo-scleral button will be inspected, then placed on an artificial anterior chamber. The epithelium of the donor will be removed mechanically. Then, one drop of riboflavin 0.1% / dextran 20% will be applied to 30 secondes for 5 minutes on the de-epithelialized cornea.The minimally manipulated normal graft-support will be forwarded to the surgeon according to standard procedure.
Receives: Procedure: De-epithelisation of the corneal graft support with instillation of riboflavin

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 day

  2. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 week

  3. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 2 weeks

  4. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    This visits will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 month

  5. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    An imaging allowing quantification of the thickness of the cornea graft-support (optical coherence tomography anterior segment) will be performed.

    Measured: 1 month

  6. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 3 months

  7. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    These visits will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: Every 2-4 months depending on the judgment of the surgeon for at least 5 years

  8. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    An imaging allowing quantification of the thickness of the cornea graft-support (optical coherence tomography anterior segment) will be performed.

    Measured: 1 year

  9. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    An imaging allowing quantification of the thickness of the cornea graft-support (optical coherence tomography anterior segment) will be performed.

    Measured: 2 years

  10. Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button

    An imaging allowing quantification of the thickness of the cornea graft-support (optical coherence tomography anterior segment) will be performed.

    Measured: 5 years

Secondary outcomes (18)
  1. Comparison of the rates of infectious keratitis between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 day

  2. Comparison of the rates of infectious keratitis between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 week

  3. Comparison of the rates of infectious keratitis between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 2 weeks

  4. Comparison of the rates of infectious keratitis between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 month

  5. Comparison of the rates of infectious keratitis between the groups

    This visits will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 3 months

  6. Comparison of the rates of infectious keratitis between the groups

    These visits will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: Every to 2-4 months depending on the judgment of the surgeon for at least 5 years

  7. Comparison of the rates of extrusion of the KPro between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 day

  8. Comparison of the rates of extrusion of the KPro between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 week

  9. Comparison of the rates of extrusion of the KPro between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 2 weeks

  10. Comparison of the rates of extrusion of the KPro between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 month

  11. Comparison of the rates of extrusion of the KPro between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 3 months

  12. Comparison of the rates of extrusion of the KPro between the groups

    These visits will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: Every to 2-4 months depending on the judgment of the surgeon for at least 5 years

  13. Comparison of the visual acuity between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 day

  14. Comparison of the visual acuity between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 week

  15. Comparison of the visual acuity between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 2 weeks

  16. Comparison of the visual acuity between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 1 month

  17. Comparison of the visual acuity between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: 3 months

  18. Comparison of the visual acuity between the groups

    This visit will include measurement of visual acuity and intraocular pressure and a full slit-lamp examination.

    Measured: Every to 2-4 months depending on the judgment of the surgeon for at least 5 years

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted3 Feb 2017 (estimated)
  2. Study start4 Jan 2017
  3. Primary completionJan 2028 (estimated)
  4. Study completionJan 2028 (estimated)

Resources

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
Triple blind
Who is masked
Participant, Care provider, Investigator
Enrolment
40 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT03041883
Sponsor's protocol ID
CE14.362
Acronym
CXL-KPro
Status last verified
Apr 2026
First submitted
25 Jan 2017
Last updated
28 Apr 2026
Results posted
No
Data monitoring committee
No
Individual data sharing
Undecided

Publications

  • Davis SA, Bovelle R, Han G, Kwagyan J. Corneal collagen cross-linking for bacterial infectious keratitis. Cochrane Database Syst Rev. 2020 Jun 17;6(6):CD013001. doi: 10.1002/14651858.CD013001.pub2.

    PubMed 32557558

Questions about this trial

What is this clinical trial studying?

A study testing Crosslinking with riboflavin of the corneal graft-support and De-epithelisation of the corneal graft support with instillation of riboflavin in people with Corneal Melting in Boston Keratoprosthesis Type I, run by Centre hospitalier de l'Université de Montréal (CHUM) at 1 site in Canada.

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 3 inclusion and 9 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: looking for participants now, as of the sponsor's last update on 28 Apr 2026. 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 Canada. 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?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Marie-Catherine Tessier (514-890-8000 ext. 11550, marie-catherine.tessier.chum@ssss.gouv.qc.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Examine whether the use of crosslinked cornea decreases the rate of corneal melting post-Kpro when compared to using a standard corneal button (time frame: 1 day). The study lists 10 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT03041883, which also lists 1 linked publication.

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 28 Apr 2026.

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