KeratoconusNCT05693740
Accelerated Corneal Collagen Crosslinking Protocols
A study testing Accelerated crosslinking (ACXL) in people with Keratoconus, run by Assiut University at 1 site in Egypt.
Trial summary
To evaluate and compare the effect of pulsed light (pl-ACXL) accelerated and continuous light accelerated (cl-ACXL) epithelium-off cross-linking in halting the progression of keratoconus. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Keratoconus
- What is being tested?
- Accelerated crosslinking (ACXL)
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 45 participants
- Where
- 1 siteEgypt
- Study dates
- 1 Aug 2022to 1 Dec 2024
- 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 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Patients with mild to moderate progressive keratoconus with maximum keratometry value Kmax < 56.0 D, Corneal thinnest pachymetry ≥ 400 µm and Corrected distance visual acuity (CDVA) equal to or better than 20/200 Snellen's acuity.
- Established keratoconus progression:
- Increase of 1.0D or more in the manifest cylinder Increase of 0.5D or more in the manifest refraction spherical equivalent Increase of 1.0D or more in Kmax Increase of 0.75D or more in Kmean decrease of 2% or more in central thickness
- Age: 18-40 y
- Clear cornea
Who cannot join
- Corneal scarring
- Previous corneal surgery
- Severe keratoconus wit non measurable refraction or Kmax ≥ 56 D or Corneal thinnest pachymetry < 400 µm
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Pulsed Light Versus Continuous Light Accelerated Epithelium-Off Cross-linking for Treatment of Progressive Keratoconus; a Prospective Comparative Study
To evaluate and compare the effect of pulsed light (pl-ACXL) accelerated and continuous light accelerated (cl-ACXL) epithelium-off cross-linking in halting the progression of keratoconus.
Read the detailed description
Keratoconus (KC), which was first described in detail in 1854, is the most common corneal primary ectasia and is characterized by progressive bilateral and asymmetric corneal thinning and bulging outward into a cone-like shape that can severely impact patients' vision.
Keratoconus usually develops in the second and third decades of life and progresses until the fourth decade. It was thought to be a rare corneal disease.
Despite a great deal of research, no one theory explains it all and it may be caused by a combination of things. However, Meek proposed that the loss of structural integrity in the KC cornea was caused by the presence of abnormal keratocytes and matrix proteins and upregulated proteolysis triggered an unravelling of lamellae along their length and from their anchors at the limbus, with an opening of the lamellar bifurcations. This theory is supported by observations following riboflavin/UVA collagen cross-linking, where the proposed cross-linkage of the tissue increases both the resistance of the stroma to enzymatic digestion and the cohesiveness between collagen fibrils and the non-collagenous matrix.
Conventional CXL (CXL) with a continuous irradiation of 3 mW/cm2 for 30 min is considered safe and effective in the prevention of keratoconus progression according to different clinical trials. nevertheless, the procedure is time-consuming, lasting around 1 h, which may lead to patient discomfort and reduced physician working efficiency.
With evolving technical advances, commercially available UV light sources have been developed, making CXL more efficient with shorter UV exposure times, higher UV intensities, and pulsed light compared with continuous light settings. Various accelerated CXL protocols have been described and its effect on biomechanical properties on corneas stated as equal to the standard protocol. Ex-vivo studies also suggest a distinction between various accelerated CXL protocols by providing evidence for a drop in efficiency with increased UV illumination intensity while maintaining equal surface energy. In this study we evaluate the two types of "accelerated crosslinking".
- Conditions
- Keratoconus
- Being tested
- Accelerated crosslinking (ACXL)
- Medical subject headings
- Keratoconus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Accelerated crosslinking (ACXL)Procedure or surgery
Epithelium-off accelerated corneal crosslinking is a procedure in which the cornea is soaked with riboflavin followed by exposure to ultraviolet irradiation in either pulsed-light or continuous-light modes to strengthen the corneal stroma and halt keratoconus progression.
| Study group | Role | What they receive |
|---|---|---|
| group 1 | Active comparator | Patients in this group will undergo pulsed light accelerated crosslinking (pl-ACXL) Receives: Procedure: Accelerated crosslinking (ACXL) |
| group 2 | Active comparator | Patients in this group will undergo continuous-light accelerated crosslinking (cl-ACXL) Receives: Procedure: Accelerated crosslinking (ACXL) |
What is being measured
The primary outcome is the main question the study is designed to answer.
1. Visual outcome measures
Uncorrected and corrected distance visual acuity (UDVA \& CDVA) using Snellen acuity chart
Measured: one year following surgery
2. Refractive outcome measures
Manifest refraction spherical equivalent (MRSE) using Topcon autorefractometer
Measured: one year following surgery
3. Topographic outcome measures
Scheimflug imaging device (Pentacam) for Diagnosis and follow up of Keratoconus after ACXL
Measured: one year following surgery
Demarcation line depth
Demarcation line depth is an outcome used to assess the success of CXL procedure using anterior segment ocular coherence tomography (AS-OCT)
Measured: 3 months following surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Jan 2023
- Study start1 Aug 2022
- Primary completion1 Dec 2024
- Study completion1 Dec 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for KeratoconusStudies of the same condition, open and under way.
- More trials run by Assiut UniversityThe 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
- Model description
- Single blinded Prospective, Interventional, randomized, comparative study
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 45 participants (actual)
Sponsor and investigators
- Lead sponsor
- Assiut University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mahmoud Abdel-Radi, Assiut University
- Investigators
- Mahmoud Abdel-Radi, MD, Principal investigator, Assiut University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05693740
- Sponsor's protocol ID
- accelerated cross-linking
- Status last verified
- Jan 2025
- First submitted
- 12 Jan 2023
- Last updated
- 29 Jan 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Zhu Y, Reinach PS, Zhu H, Li L, Yang F, Qu J, Chen W. Continuous-light versus pulsed-light accelerated corneal crosslinking with ultraviolet-A and riboflavin. J Cataract Refract Surg. 2018 Mar;44(3):382-389. doi: 10.1016/j.jcrs.2017.12.028.
PubMed 29703291
Study at a glance
From the registry record, last updated by the sponsor on 29 Jan 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pulsed Light Versus Continuous Light Accelerated Epithelium-Off Cross-linking for Treatment of Progressive Keratoconus; a Prospective Comparative Study
- ClinicalTrials.gov ID
- NCT05693740
- Acronym / sponsor ID
- accelerated cross-linking
- Conditions
- Keratoconus
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 45 participants (actual)
- Lead sponsor
- Assiut UniversityUniversity, hospital or other
- Study start
- 1 Aug 2022 (actual)
- Primary completion
- 1 Dec 2024 (actual)
- Study completion
- 1 Dec 2024 (actual)
- First posted
- 23 Jan 2023 (actual)
- 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.
To evaluate and compare the effect of pulsed light (pl-ACXL) accelerated and continuous light accelerated (cl-ACXL) epithelium-off cross-linking in halting the progression of keratoconus.
Detailed description
Keratoconus (KC), which was first described in detail in 1854, is the most common corneal primary ectasia and is characterized by progressive bilateral and asymmetric corneal thinning and bulging outward into a cone-like shape that can severely impact patients' vision.
Keratoconus usually develops in the second and third decades of life and progresses until the fourth decade. It was thought to be a rare corneal disease.
Despite a great deal of research, no one theory explains it all and it may be caused by a combination of things. However, Meek proposed that the loss of structural integrity in the KC cornea was caused by the presence of abnormal keratocytes and matrix proteins and upregulated proteolysis triggered an unravelling of lamellae along their length and from their anchors at the limbus, with an opening of the lamellar bifurcations. This theory is supported by observations following riboflavin/UVA collagen cross-linking, where the proposed cross-linkage of the tissue increases both the resistance of the stroma to enzymatic digestion and the cohesiveness between collagen fibrils and the non-collagenous matrix.
Conventional CXL (CXL) with a continuous irradiation of 3 mW/cm2 for 30 min is considered safe and effective in the prevention of keratoconus progression according to different clinical trials. nevertheless, the procedure is time-consuming, lasting around 1 h, which may lead to patient discomfort and reduced physician working efficiency.
With evolving technical advances, commercially available UV light sources have been developed, making CXL more efficient with shorter UV exposure times, higher UV intensities, and pulsed light compared with continuous light settings. Various accelerated CXL protocols have been described and its effect on biomechanical properties on corneas stated as equal to the standard protocol. Ex-vivo studies also suggest a distinction between various accelerated CXL protocols by providing evidence for a drop in efficiency with increased UV illumination intensity while maintaining equal surface energy. In this study we evaluate the two types of "accelerated crosslinking".
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
- Model description
- Single blinded Prospective, Interventional, randomized, comparative study
| Arm | Type | Receives |
|---|---|---|
| group 1 | Active comparator | Procedure: Accelerated crosslinking (ACXL)Patients in this group will undergo pulsed light accelerated crosslinking (pl-ACXL) |
| group 2 | Active comparator | Procedure: Accelerated crosslinking (ACXL)Patients in this group will undergo continuous-light accelerated crosslinking (cl-ACXL) |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Patients with mild to moderate progressive keratoconus with maximum keratometry value Kmax < 56.0 D, Corneal thinnest pachymetry ≥ 400 µm and Corrected distance visual acuity (CDVA) equal to or better than 20/200 Snellen's acuity.
- Established keratoconus progression:
- Increase of 1.0D or more in the manifest cylinder Increase of 0.5D or more in the manifest refraction spherical equivalent Increase of 1.0D or more in Kmax Increase of 0.75D or more in Kmean decrease of 2% or more in central thickness
- Age: 18-40 y
- Clear cornea
Key exclusion criteria (3 listed)
- Corneal scarring
- Previous corneal surgery
- Severe keratoconus wit non measurable refraction or Kmax ≥ 56 D or Corneal thinnest pachymetry < 400 µm
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 |
|---|---|---|
| Accelerated crosslinking (ACXL)Epithelium-off accelerated corneal crosslinking is a procedure in which the cornea is soaked with riboflavin followed by exposure to ultraviolet irradiation in either pulsed-light or continuous-light modes to strengthen the corneal stroma and halt keratoconus progression. | Procedure or surgery | group 1, group 2 |
Primary outcome
1. Visual outcome measures
Time frame: one year following surgery
Uncorrected and corrected distance visual acuity (UDVA \& CDVA) using Snellen acuity chart
2. Refractive outcome measures
Time frame: one year following surgery
Manifest refraction spherical equivalent (MRSE) using Topcon autorefractometer
3. Topographic outcome measures
Time frame: one year following surgery
Scheimflug imaging device (Pentacam) for Diagnosis and follow up of Keratoconus after ACXL
Demarcation line depth
Time frame: 3 months following surgery
Demarcation line depth is an outcome used to assess the success of CXL procedure using anterior segment ocular coherence tomography (AS-OCT)
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 29 Jan 2025.
- Background: PubMed 29703291Zhu Y, Reinach PS, Zhu H, Li L, Yang F, Qu J, Chen W. Continuous-light versus pulsed-light accelerated corneal crosslinking with ultraviolet-A and riboflavin. J Cataract Refract Surg. 2018 Mar;44(3):382-389. doi: 10.1016/j.jcrs.2017.12.028.
- Individual participant dataSharing planned: No
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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.
Mahmoud Abdel-Radi, MD principal investigator
Assiut University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Accelerated crosslinking (ACXL) in people with Keratoconus, run by Assiut University at 1 site in Egypt.
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 5 inclusion and 3 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 29 Jan 2025. 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 Egypt. 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?
1. Visual outcome measures (time frame: one year following surgery). The study lists 4 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 NCT05693740, 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 29 Jan 2025.