KeratoconusNCT05161052
Assessment of Corneal Stiffness in Keratoconus After Crosslinking by Corvis ST and OCT.
A study testing Corvis ST (dynamic Scheimpflug technology) in people with Keratoconus, run by Cairo University.
Trial summary
Objectives: Measurement of corneal stiffness parameters { Deformation Amlitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } in keratoconic corneas before and after 3 and 6 months CXL using Corvis ST. 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?
- Corvis ST (dynamic Scheimpflug technology)
- Type of treatment
- Medical device
- How many people
- 55 participants
- Where
- No sites listed yet
- Study dates
- 1 Jan 2022to 1 Feb 2023
- 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 documented progressive keratoconus within one year include any of the following:
- ≥ 1.00 diopter increase in maximal keratometry (Kmax). B. ≥ 1.00 diopter increase in the manifest cylinder. C. ≥ 0.75 diopter increase in average of Kmax and Kmin (Kmean). D. ≥ 2% decrease in central thickness. E. ≥ 1.50 diopter increase in the central K power from baseline. F. ≥ 1.0 diopter increase in manifest spherical equivalent change (MRSE).
- All patients have minimal corneal stromal thickness 400 μm before UVA irradiation.
Who cannot join
- Patients with corneal rings.
- Advanced keratoconus with corneal scarring.
- History of herpetic keratitis and severe corneal infection.
- Pregnancy or breastfeeding.
- The use of rigid contact lens¬es for more than 4 weeks before the baseline evaluation.
Trial locations and contacts
No sites are listed yet.
About this study
Official title: Assessment of Corneal Stiffness Parameters in Keratoconus After Corneal Collagen Cross Linking Using Dynamic Scheimpflug Technology and Anterior Segment Optical Coherence Tomography.
Objectives:
- Measurement of corneal stiffness parameters { Deformation Amlitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } in keratoconic corneas before and after 3 and 6 months CXL using Corvis ST.
- Measurement of demarcation line depth using anterior segment OCT and correlate between corneal stiffness following CXL and demarcation line depth.
Read the detailed description
Background and Rationale:
Keratoconus is a progressive corneal degeneration resulting from noninflammatory thinning of the corneal stroma. Visual impairment typically commences in adolescence and progresses thereafter. Further increase in myopia, irregular astigmatism, and subepithelial scarring leads to visual impairment. Treatment modalities are based on refractive correction with spectacles or contact lenses to correct astigmatism and restore visual acuity. Such modalities do not stop ectatic progression and further visual deterioration, which ultimately necessitates corneal transplantation in 10% to 20% of patients.
Corneal collagen cross-linking (CXL) has emerged as a promising techniq;ue to slow or halt the progression of keratoconus. CXL leads to an increase in intra and interfibrillar covalent bonds by photosensitized oxidation and causes a biomechanical stabilization of the cornea.
Corneal visualization using dynamic Scheimpflug technology (Corvis ST, Oculus Optikger€ate GmbH) allows in vivo measurement of the corneal biomechanical deformation response to an applied air puff and is useful for evaluating the biomechanical response parameters of the cornea. It captures the dynamic corneal deformation caused by an air puff using an ultrahigh- speed camera that operates at a speed of greater than 4300 frames per second to capture a series of 140 sequential horizontal Scheimpflug images of the temporal-nasal cross section of the cornea. The consistency of the air puff has been shown and the spatial and temporal profiles have been characterized to allow calculation of the load on the cornea within the imaging window.
The Corvis ST enables the measurement of several parameters by analyzing the timing and patterns of deformation at the highest concavity as well as applanation during inward deformation (loading) and outward recovery (unloading). The original parameters have been reported to be influenced most strongly by intraocular pressure (IOP) as well as age and central corneal thickness (CCT). Recently, new corneal biomechanical parameters were introduced, including the Deformation Amplitude ratio at 1.0 mm (DAR1), Deformation Amplitude ratio at 2.0 mm (DAR2), Integrated radius, Stiffness Parameter at first applanation (SP A1), Ambrosio's Relational Thickness (ARTH) , Corbic Biomechanical index (CBI) and biomechanically corrected IOP (bIOP).
Laboratory studies have shown that the effective depth of CXL is confined to the anterior 300 μm of the cornea. Moreover, a stromal demarcation line between treated and untreated stroma was visible biomicroscopically at a depth of approximately 300 μm over the entire cornea after CXL treatment. This demarcation line was also evident on optical coherence tomography (OCT). The depth of this line has been postulated as an indirect measurement of cross-linking effectiveness.
- Conditions
- Keratoconus
- Being tested
- Corvis ST (dynamic Scheimpflug technology)
- Medical subject headings
- Keratoconus
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Corvis ST (dynamic Scheimpflug technology)Device
Also called OCT (Optical Coherence tomography)
- Measurement of corneal stiffness parameters { Deformation Amlitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } in keratoconic corneas before and after 3 and 6 months CXL using Corvis ST.
- Measurement of demarcation line depth using anterior segment OCT and correlate between corneal stiffness following CXL and demarcation line depth
What is being measured
The primary outcome is the main question the study is designed to answer.
Measuring changes in corneal stiffness parameters in keratoconus after CXL by Corvis ST which measures corneal stiffness parameters.
Measurement of changes in corneal stiffness parameters { Deformation Amplitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } before and after crosslinking procedure to measure corneal stiffness.
Measured: Before crosslinknig procedure and after 3, 6 months using Corvis ST.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2021
- Study start1 Jan 2022 (estimated)
- Primary completion1 Jan 2023 (estimated)
- Study completion1 Feb 2023 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for KeratoconusStudies of the same condition, open and under way.
- More trials run by Cairo 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
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Single group
- Model description
- * Measurement of corneal stiffness parameters { Deformation Amplitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } in keratoconic corneas before and after 3 and 6 months CXL using Corvis ST. * Measurement of demarcation line depth using anterior segment OCT and correlate between corneal stiffness following CXL and demarcation line depth.
- Masking
- None (open label)
- Enrolment
- 55 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Cairo University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mohamed Mohamed Samir Elnoamany, Cairo University
- Investigators
- Mohamed Fakhry, MD, Principal investigator, Cairo University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05161052
- Sponsor's protocol ID
- MD-80-2021
- Status last verified
- Dec 2021
- First submitted
- 19 Oct 2021
- Last updated
- 16 Dec 2021
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Salouti R, Bagheri M, Shamsi A, Zamani M. Corneal Parameters in Healthy Subjects Assessed by Corvis ST. J Ophthalmic Vis Res. 2020 Feb 2;15(1):24-31. doi: 10.18502/jovr.v15i1.5936. eCollection 2020 Jan-Mar.
PubMed 32095205Nakao Y, Kiuchi Y, Okumichi H. Evaluation of biomechanically corrected intraocular pressure using Corvis ST and comparison of the Corvis ST, noncontact tonometer, and Goldmann applanation tonometer in patients with glaucoma. PLoS One. 2020 Sep 23;15(9):e0238395. doi: 10.1371/journal.pone.0238395. eCollection 2020.
PubMed 32966284Herber R, Terai N, Pillunat KR, Raiskup F, Pillunat LE, Sporl E. [Dynamic Scheimpflug Analyzer (Corvis ST) for measurement of corneal biomechanical parameters : A praxis-related overview]. Ophthalmologe. 2018 Aug;115(8):635-643. doi: 10.1007/s00347-018-0716-y. German.
PubMed 29767348
Study at a glance
From the registry record, last updated by the sponsor on 16 Dec 2021. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Corneal Stiffness Parameters in Keratoconus After Corneal Collagen Cross Linking Using Dynamic Scheimpflug Technology and Anterior Segment Optical Coherence Tomography.
- ClinicalTrials.gov ID
- NCT05161052
- Acronym / sponsor ID
- MD-80-2021
- Conditions
- Keratoconus
- Study type
- Interventional
- Recruitment status
- Unknown status
- Enrolment
- 55 participants (estimated)
- Lead sponsor
- Cairo UniversityUniversity, hospital or other
- Study start
- 1 Jan 2022 (estimated)
- Primary completion
- 1 Jan 2023 (estimated)
- Study completion
- 1 Feb 2023 (estimated)
- First posted
- 16 Dec 2021 (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.
Objectives:
- Measurement of corneal stiffness parameters { Deformation Amlitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } in keratoconic corneas before and after 3 and 6 months CXL using Corvis ST.
- Measurement of demarcation line depth using anterior segment OCT and correlate between corneal stiffness following CXL and demarcation line depth.
Detailed description
Background and Rationale:
Keratoconus is a progressive corneal degeneration resulting from noninflammatory thinning of the corneal stroma. Visual impairment typically commences in adolescence and progresses thereafter. Further increase in myopia, irregular astigmatism, and subepithelial scarring leads to visual impairment. Treatment modalities are based on refractive correction with spectacles or contact lenses to correct astigmatism and restore visual acuity. Such modalities do not stop ectatic progression and further visual deterioration, which ultimately necessitates corneal transplantation in 10% to 20% of patients.
Corneal collagen cross-linking (CXL) has emerged as a promising techniq;ue to slow or halt the progression of keratoconus. CXL leads to an increase in intra and interfibrillar covalent bonds by photosensitized oxidation and causes a biomechanical stabilization of the cornea.
Corneal visualization using dynamic Scheimpflug technology (Corvis ST, Oculus Optikger€ate GmbH) allows in vivo measurement of the corneal biomechanical deformation response to an applied air puff and is useful for evaluating the biomechanical response parameters of the cornea. It captures the dynamic corneal deformation caused by an air puff using an ultrahigh- speed camera that operates at a speed of greater than 4300 frames per second to capture a series of 140 sequential horizontal Scheimpflug images of the temporal-nasal cross section of the cornea. The consistency of the air puff has been shown and the spatial and temporal profiles have been characterized to allow calculation of the load on the cornea within the imaging window.
The Corvis ST enables the measurement of several parameters by analyzing the timing and patterns of deformation at the highest concavity as well as applanation during inward deformation (loading) and outward recovery (unloading). The original parameters have been reported to be influenced most strongly by intraocular pressure (IOP) as well as age and central corneal thickness (CCT). Recently, new corneal biomechanical parameters were introduced, including the Deformation Amplitude ratio at 1.0 mm (DAR1), Deformation Amplitude ratio at 2.0 mm (DAR2), Integrated radius, Stiffness Parameter at first applanation (SP A1), Ambrosio's Relational Thickness (ARTH) , Corbic Biomechanical index (CBI) and biomechanically corrected IOP (bIOP).
Laboratory studies have shown that the effective depth of CXL is confined to the anterior 300 μm of the cornea. Moreover, a stromal demarcation line between treated and untreated stroma was visible biomicroscopically at a depth of approximately 300 μm over the entire cornea after CXL treatment. This demarcation line was also evident on optical coherence tomography (OCT). The depth of this line has been postulated as an indirect measurement of cross-linking effectiveness.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Model description
- * Measurement of corneal stiffness parameters { Deformation Amplitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } in keratoconic corneas before and after 3 and 6 months CXL using Corvis ST. * Measurement of demarcation line depth using anterior segment OCT and correlate between corneal stiffness following CXL and demarcation line depth.
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (3 listed)
- Patients with documented progressive keratoconus within one year include any of the following:
- ≥ 1.00 diopter increase in maximal keratometry (Kmax). B. ≥ 1.00 diopter increase in the manifest cylinder. C. ≥ 0.75 diopter increase in average of Kmax and Kmin (Kmean). D. ≥ 2% decrease in central thickness. E. ≥ 1.50 diopter increase in the central K power from baseline. F. ≥ 1.0 diopter increase in manifest spherical equivalent change (MRSE).
- All patients have minimal corneal stromal thickness 400 μm before UVA irradiation.
Key exclusion criteria (5 listed)
- Patients with corneal rings.
- Advanced keratoconus with corneal scarring.
- History of herpetic keratitis and severe corneal infection.
- Pregnancy or breastfeeding.
- The use of rigid contact lens¬es for more than 4 weeks before the baseline evaluation.
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 |
|---|---|---|
| Corvis ST (dynamic Scheimpflug technology)Also: OCT (Optical Coherence tomography)* Measurement of corneal stiffness parameters { Deformation Amlitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } in keratoconic corneas before and after 3 and 6 months CXL using Corvis ST. * Measurement of demarcation line depth using anterior segment OCT and correlate between corneal stiffness following CXL and demarcation line depth | Device | – |
Primary outcome
Measuring changes in corneal stiffness parameters in keratoconus after CXL by Corvis ST which measures corneal stiffness parameters.
Time frame: Before crosslinknig procedure and after 3, 6 months using Corvis ST.
Measurement of changes in corneal stiffness parameters { Deformation Amplitude (DAR1), Integrated radius, Stress parameter (SP A1), Stress strain index (SSI) and Corvis biomechanical index (CBI) } before and after crosslinking procedure to measure corneal stiffness.
Results and safety
Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Dec 2021.
- Background: PubMed 32095205Salouti R, Bagheri M, Shamsi A, Zamani M. Corneal Parameters in Healthy Subjects Assessed by Corvis ST. J Ophthalmic Vis Res. 2020 Feb 2;15(1):24-31. doi: 10.18502/jovr.v15i1.5936. eCollection 2020 Jan-Mar.
- Background: PubMed 32966284Nakao Y, Kiuchi Y, Okumichi H. Evaluation of biomechanically corrected intraocular pressure using Corvis ST and comparison of the Corvis ST, noncontact tonometer, and Goldmann applanation tonometer in patients with glaucoma. PLoS One. 2020 Sep 23;15(9):e0238395. doi: 10.1371/journal.pone.0238395. eCollection 2020.
- Background: PubMed 29767348Herber R, Terai N, Pillunat KR, Raiskup F, Pillunat LE, Sporl E. [Dynamic Scheimpflug Analyzer (Corvis ST) for measurement of corneal biomechanical parameters : A praxis-related overview]. Ophthalmologe. 2018 Aug;115(8):635-643. doi: 10.1007/s00347-018-0716-y. German.
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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.
Mohamed Fakhry, MD principal investigator
Cairo University
Questions about this trial
What is this clinical trial studying?
A study testing Corvis ST (dynamic Scheimpflug technology) in people with Keratoconus, run by Cairo University.
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 5 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: status not confirmed, as of the sponsor's last update on 16 Dec 2021. Status can change between updates, so confirm with the study contact before making plans.
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?
Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
Contact Mohamed Elnoamany, MD (01222536367, mohamedelnoamany1@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Measuring changes in corneal stiffness parameters in keratoconus after CXL by Corvis ST which measures corneal stiffness parameters. (time frame: Before crosslinknig procedure and after 3, 6 months using Corvis ST.). 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 NCT05161052, which also lists 3 linked publications.
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 16 Dec 2021.