Refractive surgery

Question 1

What radiation is typical excimer laser?

Answer 1

193nm, ultraviolet region

Question 2

Why is an excimer laser suitable for refractive surgery?

Answer 2

Highly accurate
Highly repeatable
Minimal thermal effect and damage to surrounding tissue.

Question 3

How does femtosecond laser work?

Answer 3

It separates corneal tissue through photodisruption.
It creates bubbles that tear the tissue.
Ultrashort bursts of radiation 10 to the-15 seconds inn duration.

Question 4

What is energy density called?

Answer 4

Fluence mj/cm

Question 5

What benefits do phakic implants have over LASIK?

Answer 5

The induce less coma and spherical aberration.

Reversible

Question 6

What depth A/C do you need with:
ICLs
Artisan/aftiflex?

Answer 6

ICLs >2.8 for myopia, 3.0mm for hyperopia

Artisan > 2.7mm

Question 7

Which phakic lens types causes most disruption to the endothelium?

Answer 7

Anterior chamber lenses

Question 8

What minimum endothelial cell density iii required.

Answer 8

> 3500 at 21
2800 at 31
2200 at 41
2000 at 45

Question 9

What percentage of patients are within 0.5D and 1D with artiflex lenses? How many see better than 6/12?

Answer 9

75%
94%
97% better than 6/12

Question 10

What percentage of patients are within 0.5D and 1D with ICLs and how many achieve 6/12or better?

Answer 10

82%
97%
100%

Question 11

What is intracor?

Answer 11

Femtosecond cuts within cornea, in non-dominant eye. Causes central cornea to steepen.

Question 12

Are multifocal ablations unilateral or bilateral.

Answer 12

Best bilaterally

Question 13

How can you judge the visual axis to aling corneal inlays?

Answer 13

Use 1st Purkinje reflex

Question 14

What depth is Kamra inserted?

Answer 14

200um

Question 15

What does the presyblens do?

Answer 15

steepens central cornea to induce a central near add.

Question 16

How does the flexivue microlens work?

Answer 16

Increases overall refractive index causing a central near add.

Question 17

What are the disadvantages of monovision?

Answer 17

Reduced binocular v/a
Reduced stereopsis
Reduced contrast sensitivity.

Question 18

How do the rings on a diffractive lens alter with increasing add?

Answer 18

More rings

Question 19

If someone reads the whole time, how would you insert multifocal IOLs?

Answer 19

Near add in non-dominant

Question 20

If someone needs to use the computer the whole time how would you insert a multifocal?

Answer 20

Intermediate add in dominant eye

Question 21

What post-op astigmatism should be aimed for with multifocal IOLs?

Answer 21

less than 0.75DC

Question 22

How can astigmatism be managed in mIOL patients?

Answer 22

if <1.5DC use clear corneal incision opposite site
Limbal relaxing incisions
Bioptics (i.e. lens surgery + laser)
Toric mIOL

Question 23

What features are there in a piggybank lens to prevent pigment dispersion syndrome and lens touch?

Answer 23

10 degree concavity of arms meaning lens sits closer to lens away from iris.
Posterior concavity prevents IOL touch