Keratoconus

Question 1

Types of keratoconus

Answer 1

1. globus
2. oval
3. central/nipple cone

Question 2

Pellucid Marginal Degeneration

Answer 2

• bilateral inferior and peripheral thinning of cornea (ectasia
• kissing doves on topographer

PMD lacks apical corneal scarring, Rizutti’s phenomenon, Munson’s sign, and the central corneal thickness is usually normal

Question 3

Keratoconus

Answer 3

• munson’s sign
• Rizzuti’s sign
• vogt striae
• hydrops

Question 4

Terrien’s dystrophy

Answer 4

Terrien’s marginal degeneration is an uncommon but distinct variety of marginal thinning of the cornea. It causes a slowly progressive non-inflammatory, unilateral or asymmetrically bilateral peripheral corneal thinning and is associated with corneal neovascularization, opacification and lipid deposition. Degeneration may lead to a high degree of against-the-rule or oblique astigmatism.

Question 5

How to correct for keratoconus (center cone)?

Answer 5

As cone steepens, diameter becomes smaller.

Question 6

How to correct for keratoconus (center cone)?

Answer 6

As cone steepens, diameter becomes smaller.

Question 7

Three Point Touch for keratoconus

Answer 7

Central apex - light touch
Mid-peripheral bearing
Minimal clearance