Analysis of the Genotype/Phenotype Relationship in the Fuchs' Corneal Endothelial Dystrophy in France

Study Overview
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Brief Summary
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The pathophysiology of the most common corneal endothelial dystrophies (Fuchs' Corneal Endothelial Dystrophy, FECD) is beginning to be dismembered. There is a significant heterogeneity in the clinical forms and the investigators have just highlighted a great diversity of histological forms that seem to define distinct groups.

Detailed Description
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The most frequent genetic abnormalities have been published since 10 years and can now be easily searched. This study is going to analyze the relationships between clinical, histological and genetic forms in a large population to better understand how histological abnormalities are formed.

Official Title
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Analysis of the Genotype/Phenotype Relationship in the Fuchs' Corneal Endothelial Dystrophy in France. The French Fuchs' Follow-up Study (Phase 2), F3S2

Conditions
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Corneal Dystrophies

Intervention / Treatment
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* Genetic: Genotyping
* Diagnostic Test: Histology
* Other: Collection of data


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: affiliated with or entitled to a social security scheme Consent form to participate in the study signed with an FECD certified by slit lamp examination requiring an endothelial keratoplasty Exclusion Criteria: - Patients under guardianship or curators

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with FECD<br>Patients with Fuchs Endothelial Corneal Dystrophy (FECD). They will have a collection of data and a blood sample | Genetic: Genotyping<br>* Genotyping will measure the triple nucleotide repeat in the TCF4 gene and search for other known mutations in other genes Blood sample will be performed (genetic analyses).<br>Diagnostic Test: Histology<br>* Histology will be performed on flat mounted Descemet membrane obtained after Descemetorhexis<br>Other: Collection of data<br>* Collection of data of examination for diagnosis of the Fuchs Endothelial Corneal Dystrophy (FECD) including slit lamp results will be performed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of CTG triplet repetitions in the intron of the Transcription Factor 4 (TCF4) gene | Polymerase Chain Reaction (PCR) will be performed from DNA (blood sample) | At inclusion | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Refraction with the auto-refractor tonometry | Analysis refraction with the auto-refractor tonometry non-contact air. | At inclusion | 
| ETDRS scale (international standardized Early Treatment Diabetic Retinopathy Study scale) | ETDRS (Early Treatment Diabetic Retinopathy Study) scale will be allowed to measure visual acuity uses an eye chart with 5 letters per line. The scores range from 0 (no letters read correctly) to 100 (all letters read correctly). | At inclusion | 
| Corneal thickness in Optical Coherence Tomography (OCT) | Corneal thickness measured by OCT in micrometers | At inclusion | 
| Diameter of the dilated pupil (mm) | Measured by contact or non-contact biometry | At inclusion | 
| Thickness of the lens (mm) | Measured by contact or non-contact biometry | At inclusion | 
| Depth of the anterior chamber (mm) | Measured by contact or non-contact biometry | At inclusion | 
| Endothelial cell density measurement (cells/mm2) | Endothelial cell density (cells/mm2) in the center and in the 4 standardized cardinal positions high low nasal temporal. | Immediately after surgery of corneal transplantation | 
| Crystalline analysis | Crystalline : clear lens, cataract, intraocular implant, aphakic | Immediately after surgery of corneal transplantation | 
| Family cases of Fuchs' Corneal Endothelial Dystrophy | Family cases: absent/probable/advanced | At inclusion | 
| Frequency of the mutation rs613872 in the intron of the Transcription Factor 4 (TCF4) gene. | PCR reactions will be performed from DNA (blood sample) | At inclusion | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Corneal Dystrophies, Corneal Endothelial Dystrophy, Fuchs' Corneal Endothelial Dystrophy, FECD