Corneal Ectasias

Question 1

which ectasia is a rare, progressive peripheral corneal thinning disorder

Answer 1

pellucid marginal degeneration

Question 2

when is the onset of pellucid marginal degeneration

Answer 2

2nd-5th decade of life

Question 3

these signs are indicative of which ectasia:

• bilateral & slowly progressive band of corneal thinning from 4-8 o’clock
• marked steepening just superior to the thinned zone
• intact epithelium & no vascularization
• severe astigmatism & steepening of inferior cornea

Answer 3

pellucid marginal degeneration

Question 4

when corneal topography shows a “kissing-dove” pattern, what ectasia is this indicative of

Answer 4

pellucid marginal degeneration

Question 5

how can you manage pellucid marginal degeneration

Answer 5

• RGP CLs
• collagen cross-linking (if progression in steepening)
• surgery (if astigmatism can’t be corrected by other options)

Question 6

which ectasia is an extremely rare condition that can be congenital or acquired

Answer 6

keratoglobus

Question 7

if keratoglobus is congenital, what must you differentiate it from

Answer 7

congenital glaucoma

Question 8

these signs are indicative of which ectasia:

• cornea develops globular ectasia & corneal thinning is generalized
• corneal hydrops are rare
• cornea is prone to rupture from mild trauma

Answer 8

keratoglobus

Question 9

these clinical findings are indicative of which ectasia:

• irregular retinoscopy reflex
• irregular astigmatism
• globular protrusion of cornea
• diffuse corneal thinning
• normal corneal diameter

Answer 9

keratoglobus

Question 10

how do you manage keratoglobus

Answer 10

• protective eyewear (polycarbonate)
• avoid contact spots
• RGP CLs

Question 11

if keratoglobus perforates, how do you manage it

Answer 11

surgery

Question 12

which ectasia is a progressive disorder that begins during puberty, progresses into 3rd-4th decade of life, then stabilizes

Answer 12

keratoconus

Question 13

what are the 3 syndromes keratoconus is associated with

Answer 13

down syndrome
Ehlers-Danlos
Marfan

Question 14

pts with vernal keratoconjunctivitis or an atopic disease that causes persistent eye rubbing can be associated with which ectasia

Answer 14

keratoconus

Question 15

these signs are indicative of which ectasia:

• Charleaux oil drop reflex
• irregular scissor reflex on ret
• Vogt Striae
• Fleischer ring
• Munson’s sign
• progressive corneal protrusion in a cone configuration w/ apical thinning
• steep keratometry readings

Answer 15

keratoconus

Question 16

these clinical findings are indicative of which ectasia:

• stromal thinning in central/paracentral cornea
• apical protrusion of cornea
• high irregular astigmatism

Answer 16

keratoconus

Question 17

assessment of what can lead to an earlier diagnosis of keratoconus

Answer 17

posterior corneal curvature

Question 18

the keratoconus grading scale is based on what

Answer 18

the highest axis of corneal power on keratometry

Question 19

a mild keratoconus will have what keratometry reading

Answer 19

< 48D

Question 20

a moderate keratoconus will have what keratometry reading

Answer 20

48-54D

Question 21

a severe keratoconus will have what keratometry reading

Answer 21

> 54D

Question 22

progression of keratoconus has a consistent change in at least two of what characteristics?

Answer 22

• steepening of anterior corneal surface
• steepening of posterior corneal surface
• thinning &/or an increase in rate of corneal thickness change

Question 23

how can you optimize VA in keratoconus

Answer 23

• spectacles in early stages
• RGP CLs
• scleral CLs

Question 24

what surgeries can be done to treat keratoconus

Answer 24

• intrastromal corneal ring segment implantation
• corneal crosslinking
• corneal transplant in severe cases

Question 25

which keratoconus surgery is more common & what does it do

Answer 25

corneal crosslinking → slows disease progression

Question 26

what is contraindicated in pts w/ keratoconus

Answer 26

refractive surgery (LASIK)

Question 27

what is the procedure for corneal crosslinking

Answer 27

riboflavin (vitamin B2) is combined with UV-A radiation

Question 28

what does corneal crosslinking do

Answer 28

strengthens corneal tissue

Question 29

how do intrastromal corneal ring segments work

Answer 29

• alter morphology of cornea

- alter refractive power of cornea

Question 30

what is an acute break in Descemet’s membrane

Answer 30

corneal hydrops

Question 31

which ectasia occurs when fluid leaks into stroma, causing significant corneal swelling & opacification

Answer 31

corneal hydrops

Question 32

these symptoms are indicative of which ectasia:

• acute decreased VA
• conjunctival hyperemia
• significant pain
• significant photophobia

Answer 32

corneal hydrops

Question 33

these are all treatments for which ectasia:

• cycloplegia
• Muro 128 (hyperosmotic gel/drop that dehydrates stroma)
• topical NSAID
• bandage soft CLs

Answer 33

corneal hydrops

Question 34

when ophthalmological intervention is needed for corneal hydrops, what do they do

Answer 34

anterior chamber gas bubble to speed up recovery