Cornea Dystrophy Flashcards
As a general rule, what are 4 characteristic of corneal dystrophies?
- Present early in life
- Autosomal Dominant
- Involve a single layer
- Demonstrate asymmetry
What is the pathogenesis of Meesman’s Corneal Dystrophy?
Nodular thickening of basement membrane. Bowman’s is normal. Cytoskeletal Intermediate Filaments are not made properly and the fragile cell degenerates early, which leads to the formation of intraepethelial microcysts
What is the pathogenesis of Map-Dot-Fingerprint Dystrophy?
Abnormal basement membrane due to fucked up hemidesmosomes. The epithelium isn’t attached strongly to the basement membrane so fluid and debris builds up under the epithelial cells leading to cysts and reduplication of basement membrane
What dystrophies have been linked to mutations on the BIGH3 gene?
- Granular Dystrophy
- Reis-Buckler / Thiel-Behnke
- Lattice Dystrophy
How do you treat Recurrent Corneal Erosions? (1st Line, 2nd Line, 3rd Line)
1st Line: Medical Tx with Artificial Tears, Steroids, and Doxycycline
2nd Line: Anterior Stromal Puncture
3rd Line: Phototherapeutic Keratectomy
What is the pathogenesis of Reis-Buckler Dystrophy?
Bowman’s Layer gets totally shattered, thinned out, or is completely absent. Replaced with multilaminar sheets of fibrous tissue and pannus. The epithelium doesn’t adhere well
What is the only real difference between Reis-Buckler and Thiel-Behnke?
TBD usually presents with more of a reticular mesh / honeycomb appearance
What is the pathogenesis of Schynder Crystalline Dystrophy?
Local abnormal cholesterol metabolism leading to crystalline opacities in the anterior stroma
What is the pathogenesis of Granular Dystrophy?
BIGH3 mutation leads to hyalin deposition starting in the central corneal stroma and progresses posteriorly
What is the most common stromal dystrophy?
Lattice Corneal Dystrophy
When do patients typically first experience RCE with Lattice Dystrophy?
First decade
What is the pathogenesis of Lattice Dystrophy?
BIGH3 mutation leads to amyloid deposits
Macular Dystrophy and Granular Dystrophy can appear similar. What would help you distinguish the two from each other?
Macular Dystrophy would show central and peripheral corneal clouding
Granular Dystrophy would show intervening corneal clearance
What type of patients would you expect to present with Corneal Macular Dystrophy?
Inbreeders (consanguineous marriages)
What is the pathogenesis of Corneal Macular Dystrophy?
Faulty metabolism of glycosaminoglycans which leads to rupture of cells and deposition of mucopolysaccharides. Occurs in the stroma but progresses posteriorly to fuck up the endothelium -> Guttata
