The Genetic Mysteries of the Corneal Dystrophies The Genetic ...

More documents

Recommendations

Info

Features of Corneal Dystrophies andDegenerationsCorneal Degenerations (Examples)Feature Dystrophy DegenerationAge of Onset Early LateFamilial Yes NoSymmetry Symmetric AsymmetricInvolved Eye Bilateral UnilateralLocation Central PeripheralVascularity No YesInflammation No YesAssoc. disorders Rarely More frequent• Arcus senilis• Vogt’s limbal girdle• Marginal furrowdegeneration• Terrien’s degeneration• Pterygium• Salzmann’s nodulardegeneration• White ring of Coats• Band keratopathy• Corneal ectasias• Keratoconus• Non-hereditary• Pellucid MarginalDegenerationKeratoconus: Degeneration or Dystrophy?• Ectasia or thinning of the cornea-usually inferior/temporally• Hereditary in some cases• Autosomal dominant• Defective genes on chromosome 21 (SOD1 and VSX genes)• Etiology not known in non-hereditary cases-suspected causes:• eye rubbing• CL wear• Hormonal• Exacerbated by pregnancyClassification of the Corneal Dystrophies• Traditionally, classified by the affected corneal layer• Molecular genetics are changing this classification• Chromosome 1 Chromosome 4• Chromosome 5 Chromosome 9• Chromosome 12 Chromosome 16• Chromosome 17 Chromosome 20• Chromosome 21 X-chromosomeIC3D-2008 Classification of CornealDystrophies• Category 1: well-defined; gene mapped;mutations known• Category 2: well-defined; mapped to specificchromosomal loci but gene not yet identified• Category 3: well-defined; not mapped to anychromosomal locus• Category 4: suspected corneal dystrophyEpithelial Dystrophies• Epithelial Basement Membrane Dystrophy(EBMD) –Map/Dot/Fingerprint or Cogan’s• Meesman’s Dystrophy• Anterior Membrane Dystrophy• Band-shaped/Whorled Microcystic Dystrophy(Lisch dystrophy)• Recurrent Corneal Erosion Dystrophy2
Epithelial Basement Membrane Dystrophy(Map-Dot-Fingerprint Dystrophy)• Most common anterior dystrophy• Not always a true dystrophy (may be aquired asopposed to inherited)• Corneal opacities:• Maps• dots (microcysts)• Fingerprint (swirls)• bleb (putty) opacities• Painful recurrent epithelial erosions after 3rd decadeDifferentiate from other etiologies ofcorneal whorling…• Fabry disease• X-linked recessive; 1:40,000 males ; 2:40,000 females• Enzyme deficiency=accumulation of glycosphingolipids• Systemic problems• Renal, cardiac, strokes, pain• Diagnosed with genetic testing (Genzyme)• Amiodarone therapy• Treatment for atrial fibrillation (rapid heart beat)FABRY DISEASEAMIODARONE THERAPY3
Page 1: The GeneticMysteries of theCorneal
Page 6 and 7: Autosomal Dominant Recurrent Cornea
Page 8 and 9: Granular Dystrophy• Opacities con
Page 11 and 12: Lattice Dystrophy Type II• Associ
Page 13 and 14: Central “Crystalline” Dystrophy
Page 15 and 16: Pre-Descemets Dystrophy• Fine, de
Page 17 and 18: Treatment of Fuch’s Dystrophy•
Page 19 and 20: Posterior Polymorphous Dystrophy•

The Genetic Mysteries of the Corneal Dystrophies The Genetic ...

Create successful ePaper yourself

Delete template?

Save as template?