Corneal ectasia

Question 1

What is keratoconus? 4

Answer 1

• bilateral
• 50% of corneal thickness has decreased
• usually at central and paracentral region
• one eye leads and the other lags

Question 2

What is pellucid marginal degeneration PMD? 4

Answer 2

• occurs from 20s-40s
• thinning at the inferior peripheral region of the cornea
• rare
• bilateral

Question 3

Signs of keratoglobulus 5

Answer 3

• limbus to limbus thinning
• often thinner at the edges
• not as steep as KC
• cone of thinning 75-90% of cornea
• blue sclera - suggests collagen synthesis problems
• corneo-neovascularisation possible