An interventional study of cross-linking surgery or intra corneal ring and abstention in Keratoconus, sponsored by University Hospital, Montpellier. Recruiting at 1 site in France. Open to participants aged 10 Years to 40 Years. Per ClinicalTrials.gov, last updated 2025-09-05.
Sponsored by University Hospital, Montpellier · Not applicable, Interventional, and Health services research
Primary objective :
Description of keratoconus at baseline and during progression in 200 participants followed by the ophthalmology departments of CHU Montpellier, CHU Bordeaux and CHU Toulouse during a 2-year period. Clinical outcome, histology of the cornea and tears proteomics will be assessed in 4 groups at different points in time:
Visits for surgery participants will be set at D7, 1 month, 6 months, 12 months and 24 months after the procedure: cross-linking or placement of the intra corneal ring.
Secondary objective :
Description of the association between clinical outcomes, histological progression of the cornea and tears proteomics in time, 2 years period.
Comparison of tears proteomics in 36 participants with keratoconus followed at CHU of Montpellier and healthy participants at baseline .
This trial is a prospective cohort study of 200 participants with keratoconus followed by the ophthalmology departments of CHU Montpellier, CHU Bordeaux and CHU Toulouse during a 2-year period. If both eyes are affected, each will be evaluated considering their own visit agenda. Histological and proteomic evaluations will be performed in 36 participants's eyes whose initial management is abstention of surgery (12 participants), cross-linking (12 participants) or intra corneal ring (12 participants).
The target population consist of participants with clinical keratoconus (topographic Rabinowitz criteria with slit lamp abnormalities and visual impairment), preclinical or crude keratoconus (abnormal or suspicious topography with normal slit lamp examination and normal visual acuity). They will be aged between 10 and 40 years included.
The follow-up will be taken care off by the ophthalmology departments of the Montpellier University Hospital, Bordeaux University Hospital or Toulouse University Hospital Collection of written informed consent, after a period of reflection, will be necessary for adult participants. For minors: informed consent will have to be signed by at least one of the 2 parents or legal guardians, and approval from the child will be asked after a period of reflection. All participants will have to be affiliated to the French social security system or beneficiary of such a system.
Description of the study course:
No therapeutic intervention outside of routine care will be performed. Depending on the therapeutic orientation, the follow-up is carried out as follows:
In this study, participants will be followed for a maximum of 2.5 years. In addition to the description of keratoconus progression, we will take a tear sample using the Schirmer test to create a biobank. This tears collection will be performed in 36 participants followed at the Montpellier University Hospital, at inclusion and at short-term follow-up visit (6 months if abstention, 1 month if surgery).
Judging criteria:
Prevalence of risk factors: a survey will measure the prevalence of risk factors for keratoconus:
This self-survey will be completed at the inclusion visit and at the last follow-up visit (M24). The time to complete this questionnaire is approximately 10 minutes.
313 studies on the registry are indexed under Keratoconus; 56 are open to participants now.
This study's planned enrollment of 200 is above the median of 40 across 205 interventional studies indexed under Keratoconus.
Browse Keratoconus studies →University Hospital, Montpellier is the lead sponsor of 1,261 studies on the registry; 224 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
After keratoconus diagnosis the patient won't be assigned to intervention
Other: abstention
After keratoconus diagnosis the patient was assigned to cross linking surgery or intra corneal ring surgery
Procedure: cross-linking surgery or intra corneal ring
After keratoconus diagnosis the patient was assigned to surgery
No surgery
Keratoconus clinical progression (Keratometry map)
Modelisation of refraction measurements in diopters, by corneal elevation topography (Orbscan and Pentacam), giving an additional indicator of the corneal deformity. High values of diopter correspond to positive bulges of the cornea. A topographic axial map will be acquired to monitor minimal and maximal keratometry. These measurements will be taken at baseline and compared for reference of progression at each visit for each eye. Keratoconus definition according to Rabinowitz (Rabinowitz YS, 1989) criteria: * Corneal asymmetry greater than 1.5 diopters (D), between the upper and lower part of the cornea, on the median vertical axis. * Central corneal power (Kmax) \> 47.2 D, measured at the top of the cone. * Asymmetry of central keratometry \> 1D between the two eyes
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
Keratoconus clinical progression (Pachymetric map)
Thickness of the cornea will be assessed in microns (µm) at several locations and will be presented as a map by corneal elevation topography (Orbscan and Pentacam). The pachymetric map will be acquired at baseline and compared for reference of progression at each visit for each eye. The higher and lower thickness points will be notified for the anterior and posterior parts of the eye.
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
Keratoconus clinical progression (Visual acuity test)
Visual acuity test with and without correction: decimal and Parinaud scales secondarily translated in LogMar.
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
Keratoconus clinical progression (Biomicroscopic examination of the cornea)
A biomicroscopic examination of the cornea in search of signs that may modify the therapeutic indications i.e : Fleischer rings (iron deposits in the lower part of the bulge, due to the stagnation of tears), visible corneal nerves, corneal opacities (due to scar tissue)
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
ABCD grading of keratoconus
Grading of the keratoconus, according to the ABCD classification : * A: keratometry of the anterior surface of the cornea (Anterior radius of curvature (ARC)), in the area of 3 mm centered by the thinnest point. * B: keratometry of the posterior surface of the cornea (Back or posterior radius of curvature PRC), in the 3mm area centered by the thinnest point. * C: thinnest point of the Cornea, i.e. minimum pachymetry. * D: Distance best corrected vision: visual acuity with the best correction, measured in 10° or in the Parinaud scale.
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
Keratoconus histological progression - Confocal microscopy (tissue thickness)
Histological degradation of the cornea taken at baseline for reference. The confocal microscope allows longitudinal analysis making it possible to carry out comparative qualitative and quantitative analyzes of the corneal tissue during time. In keratoconus, this technique is possible to highlight a reduction in basal plexus nerve density and poorer anterior stromal cell density compared to healthy subjects. Tissue thickness in microns (µm)
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
Keratoconus histological progression - Confocal microscopy (Cellular organization)
Histological degradation of the cornea taken at baseline for reference. The confocal microscope allows longitudinal analysis making it possible to carry out comparative qualitative and quantitative analyzes of the corneal tissue during time. In keratoconus, this technique is possible to highlight a reduction in basal plexus nerve density and poorer anterior stromal cell density compared to healthy subjects. Cell organization and morphology. Image acquisition. * Colonization by inflammatory cells (yes/no), increased nucleo/cytoplasmic ratio (yes/no), hyperreflectivity of the nuclei (yes/no). * Nerve density of the basal plexuses of normal appearance (yes/no), straight with branches (yes/no), normal hyperreflectivity (yes/no)
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
Keratoconus histological progression - Confocal microscopy (Cellular density)
Histological degradation of the cornea taken at baseline for reference. The confocal microscope allows longitudinal analysis making it possible to carry out comparative qualitative and quantitative analyzes of the corneal tissue during time. In keratoconus, this technique is possible to highlight a reduction in basal plexus nerve density and poorer anterior stromal cell density compared to healthy subjects. Cellular density (number). Image acquisition. \- Cell count in the different layers, corneal nerve count from the basal plexus to the corneal apex
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
Keratoconus histological progression - Confocal microscopy (Light scattering)
Histological degradation of the cornea taken at baseline for reference. The confocal microscope allows longitudinal analysis making it possible to carry out comparative qualitative and quantitative analyzes of the corneal tissue during time. In keratoconus, this technique is possible to highlight a reduction in basal plexus nerve density and poorer anterior stromal cell density compared to healthy subjects. Light scattering in vivo, measurement of corneal deformity. Diopter.
Time frame: Baseline vs Visit at 1 month/6 months/12 months/24 months
Risk factors - Questionnaire
* Presence of atopy/allergy * Eye rubbing * Family medical history * Ethnicity * Smoking habits * Dry eye syndrome
Time frame: Baseline vs 24 months
Tears proteomics
For 36 participants from Montpellier. Composition and evolution of tears determined by proteomic analysis
Time frame: Baseline vs Visit at 1 month/6 months
ABCD class worsening between consultations
At baseline and during follow-up
Time frame: Baseline vs Visit at 1 month/6 months - Baseline vs 12 months - Baseline vs 24 months
Keratoconus histological evolution
Comparison of confocal microscopy results from primary outcomes through time.
Time frame: Baseline vs Visit at 1 month/6 months
Proteomic profile evolution
Difference between the composition of tears from healthy participants and from keratoconus patients from baseline to short term follow up.
Time frame: Baseline vs Visit at 1 month/6 months
Plan to share: Undecided
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
University Hospital, Montpellier →