Corneal Surgeries and CL considerations

Question 1

Hydrops are a break in which layer(s)?

Answer 1

Descemet’s membrane and underlying endothelium

aqueous humor leaks into the stroma leading to edema

Question 2

What are symptoms of hydrops?

Answer 2

sudden onset decreased vision, irritation/ pain; photophobia

Question 3

What are the signs of hydrops?

Answer 3

observable break in Descemet’s membrane, anterior and posterior stromal edema with possible epithelial involvement, and hyperemia of the conjunctiva

patients may notice a white spot on their eye

Question 4

Hydrops can be found with which disorders?

Answer 4

Keratoconus, PMD; post-lasik, post RK or post-PKP ectasias

Question 5

How long does it take for hydrops to resolve?

Answer 5

3-6 months

monitor monthly dt potential for neovascular hydrops

Question 6

When no epithelial compromise, can treat conservatively….

What is the supportive therapy for Hydrops?

Answer 6

artificial tears PRN

topical NSAID or steroid TID-QID for pain and inflammation

Question 7

Gas/ Air may be injected intracamerally to treat hydrops; what does this prevent?

air, perfluoropropane (C3F8) or hexafluoride (SF6)

Answer 7

aqueous humor from entering descemet’s and the stroma

faster healing of corneal endothelial cells

Question 8

Why might hydrops be considered a blessing in disguise?

Answer 8

There may be a flattening effect with scar formation

easier to fit corneas that were initially too steep

Question 9

What are the contact lens options for hydrops?

Answer 9

Corneal GP; Piggyback system; specialty soft lenses; hybrids; sclerals

GP: larger diameter; RoseK or reverse geometry; SCL: rigid modulus/ thicker

Question 10

What is crosslinking used for?

Answer 10

Strengthening collagen fibers in the cornea; prevent further progression of KC

Question 11

Is epi-on or epi-off the FDA approved technique for CXL?

Answer 11

Epi-off

Question 12

What is a benefit of epi-off CXL?

Answer 12

Riboflavin saturates the cornea faster and deeper than with epi on

Question 13

What are the benefits of epi-on CXL?

Answer 13

less invasive; less painful; faster recovery

Question 14

What are the adverse affects of CXL?

Answer 14

punctate keratitis, corneal striae, corneal epithelium defect, eye pain, reduced visual acuity; corneal opacity/ haze

reduced VA: up to 6 months to resolve

Corneal haze: up to 12 months to resolve; or permanent

Question 15

What signs of KC progression can qualify a patient for CXL?

Answer 15

• increase in steepest K by >/= 1.00D
• Increase in regular astigmatism during refraction >/= 1.00 D
• myopic shift during refraction (SE, >/= 0.50 D)
• Steepening of BCR of corneal GP >/=0.10 mm

Must have at least one

Question 16

How many cross-linking procedures will a patient need?

Answer 16

typically just one

follow up every 6 month to monitor for progression

Question 17

How long should patients stay out of CL’s before CXL?

Answer 17

1-2 weeks before consultation visit; 3 days before procedure

Question 18

When are contacts re-fit after CXL?

Answer 18

1 month follow up

Question 19

What material are Intacs made of?

Answer 19

PMMA

Question 20

What is the name of the alternative to Intacs made from corneal donor tissue?

Answer 20

CAIRS

Question 21

What is CXL Plus?

Answer 21

Cross linking combined with refractive procedure (PRK, ring segments, phakic IOL implant, refractive lens surgery)

Question 22

What is the oral alternative to CXL that is being studied?

Answer 22

Mega-dose riboflavin and sunlight (without eye protection from the sunlight)

sun exposure for 15 min/ day at peak UV index

Question 23

Which surgical procedures are used for the anterior layers of the cornea?

Answer 23

SK and PTK

PTK removes deeper layers of tissue

Question 24

What conditions can SK/ PTK be used to treat?

Answer 24

EBMD, Recurrent corneal erosions, Salzmann’s nodular degeneration, calcific band keratopathy, superficial corneal scar

Question 25

Penetrating keratoplasty replaces which layers of the cornea?

Answer 25

All of them

Question 26

What is a complication of PK/PKP?

Answer 26

secondary, high, irregular astigmatism (and subsequent anisometropia)

slow recovery

CL refit at 12 months post-op or earlier if stable

Question 27

Which layer(s) does DALK replace with donor tissue?

Answer 27

Stroma

endo and descemet’s are retained

Question 28

What are the indications for DALK?

Answer 28

KC, stromal scars, dystrophies

diseases not involving the endothelium

Question 29

Which layers are replaced during DSAEK?

Answer 29

Descemet’s membrane and endothelium

donor tissue includes thin layer of posterior stroma

Question 30

Which procedure uses an air bubble to attach donor tissue to the the recipient stroma without sutures?

donor tissue: DM, endothelium and thin layer of posterior stroma

Answer 30

DSAEK

Descemet’s Stripping Automated Endothelial Keratoplasty

Question 31

Which device uses a host-tissue friendly outer skirt with a high affinity for recipient rim tissue with a host-tissue unfriendly central clear optical region that has a low affinity for host tissue?

Answer 31

Boston Keratoprosthesis

Usually done with removal of crystalline lens

Question 32

What common test can not be done with the Boston Keratoprosthesis?

Answer 32

tonometry

Question 33

What topical meds will a patient need for life after K-Pro?

Answer 33

topical antibiotic, topical steroid, topical glaucoma med