Keratoconus

Question 1

What is the Definition of Corneal Ectasia?

Answer 1

Thinning of the central, paracentral or peripheral cornea due to corneal dystrophies or degredation

Question 2

What is the difference between Corneal Dystrophy and Corneal Degeneration

Answer 2

Corneal Dystrophies are,

• usually bilateral (symmetrical)
• Inherited disorders
• Genetic basis
  - Autosomal dominant
  - Multiple family members are affected

Corneal Degenerations are,

• usually unilateral (asymmetric)
• Acquired disorders (Environmentl +/- genetic predisposition.
  - Inflammation
  - Secondary to systemic conditions
  - Medications
  - Infections
  - trauma

Question 3

Explain the 4 categories for corneal dystrophies by the IC3D?

Answer 3

Category 1 - Well defined, responsible gene mapped and identified, specific mutation known

Category 2 - Well defined, mapped to 1 or more specific chromosomal loci, but Genes unknown

Category 3 - Well defined, disorder has not yet been mapped to chromosomal locus

Category 4 - Suspected new or previously documented, corneal dystrophy, Unconvincing evidence that it is a separate entity.