Pr Eric E. GabisonOphthalmology · Cornea & refractive · Paris
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Home › Pro area › Corneal dystrophies › François fleck dystrophy, or "fleck corneal dystrophy"
Course contents ▾
  1. Introduction & atlas
  2. Anterior dystrophies
  3. Meesmann juvenile epithelial dystrophy
  4. Lisch epithelial dystrophy
  5. Gelatinous drop-like dystrophy
  6. Cogan dystrophy
  7. Reis-Bücklers dystrophy
  8. Thiel-Behnke dystrophy
  9. Stromal dystrophies
  10. Lattice dystrophy
  11. Granular dystrophy
  12. Macular dystrophy, or Groenouw type II
  13. Schnyder crystalline dystrophy
  14. François fleck dystrophy, or "fleck corneal dystrophy"
  15. Posterior amorphous corneal dystrophy
  16. Endothelial dystrophies
  17. Posterior polymorphous corneal dystrophy
  18. CHED
  19. Fuchs dystrophy
  20. Synthesis
  21. Tables & references
Stromal dystrophies

François fleck dystrophy, or "fleck corneal dystrophy"

Stromal

Group
Stromal
Layer
Stromal keratocytes
Gene
PIKFYVE (anciennement PIP5K3), 2q34
Inheritance
AD
Age of onset
Congenital, found incidentally
Symptom
Asymptomatic; acuity preserved
Treatment
None
Recurrence
Greffe non nécessaire
Layer involvedCOUCHE ATTEINTEStroma antérieurStromaStroma postérieur
Cues: AD/AR inheritance · graft recurrence +++ high ++ intermediate + low · bold = key terms · Differential diagnosis (blue) and Treatment (amber) boxes.
The pitfall

Often asymmetrical, sometimes unilateral — rare among dystrophies.

Genetics and background

History
First described by François and Neetens
Genetics
AD
Mutation
Chromosome 2q35, mutation of the phosphoinositide kinase, FYVE finger-containing gene (PIKFYVE), formerly known as type III phosphatidylinositol-3-phosphate/phosphatidylinositol-5-kinase (PIP5K3).
Laterality
Bilateral
Symmetry
No
Age of onset
The abnormality is present from birth but is rarely diagnosed, since the majority of patients are asymptomatic.
Location
The keratocytes; this abnormality is present only in some keratocytes and not in all keratocytes.

At the slit lamp

Appearance:

Direct illumination
discrete translucent to gray-white punctate stromal opacities, distributed regularly and homogeneously from limbus to limbus, sparing Bowman layer as it is acellular. The specks may take on various appearances: circular, oval, star-shaped, or comma-shaped.
Retroillumination
The deposits have a refractile appearance.

Symptoms and course

Pain or recurrent erosion
No
Visual acuity
Usually preserved; patients are often asymptomatic.

Diagnosis

Diagnosis:

  • Histology: it is a combination of deposits similar to those of macular dystrophy and Schnyder dystrophy. The affected keratocytes are vacuolated by two substances: GAG (within membranous vacuoles), Alcian +, and lipids (in vacuoles smaller than the GAG vacuoles), Sudan black +.
  • Electron microscopy: pleomorphic or linear extracellular vacuoles, sometimes with dense fibrillogranular membranous material, within certain keratocytes, resembling the inclusions found in macular dystrophies and in the mucopolysaccharidoses.
  • Confocal microscopy: discrete gray-white stromal opacities corresponding to deposits of pathological material within keratocytes with enlarged nuclei, with inclusions in the basal corneal nerves.
  • Corneal hypoesthesia may develop.

Treatment

Treatment

Not necessary