Laser Surgeries + Ocular motility tests Flashcards
What are the 3 kinds of laser surgeries?
1) LASIK - Laser assisted in situ keratomileusis
2) PRK - Photorefractive keratectomy
3) SMILE - Small incision lenticule extraction procedure
What are 2 non laser surgeries?
1) Phakic IOL - Phakic intraocular lens
2) RLE - Refractive lens exchange
What 2 kinds of lasers are used in laser surgery?
Excrimer lasers
Femtosecond Lasers
What years did health canada approve each laser surgeries ?
PRK - 1990
LASIK - 1994
SMILE - 2015
Which procedures are used for myopia? (5)
PRK
LASIK
PHAKIC IOL
RLE
SMILE
What procedures are used for hypermyopia? (4)
PRK
LASIK
RLE
PHAKIC IOL (with limitations)
What is the difference between how the 3 laser surgeries are done?
PRK involves using a laser to the epithelium layer of the cornea
LASIK flips the layer of the cornea over
SMILE uses a small incision and doesn’t disturb the top layer of the cornea
What are 3 pros to PRK?
No flap
Can be done on a thinner cornea
effective and safe procedure
What are 5 cons to PRK?
slower healing
epithelium layer removed
delayed epithelium healing
discomfort
light sensitivity
What are 2 pros of LASIK?
LASIK is quick and safe
results come quickly
What are 3 issues with LASIK?
Not everyone is eligible (thinner corneas)
You may need to get LASIK done again
Issues with the flap - position/folds/debris beneath it
What is a pro with SMILE?
corneal sensitivity recovered faster
What are 2 cons with SMILE?
less-smooth cuts
more limited for patients
What are 3 characteristics of Phakic IOL?
treats high myopia and astigmatism
procedure is reversible
2 locations for the phakic IOL - anterior/posterior chamber
What is a pro with Phakic IOL?
No tissue is removed for no induced dry eye
What is a con with Phakic IOL?
Anterior chamber positioned IOL are associated with corneal endothelial cell loss
What are 3 characteristics with RLE?
Better for High prescriptions and people with early lenticular changes
Presbyopes requiring correction in distance, intermediate and near vision.
Prefered for patients with shallow anterior chamber or low endothelial cell count
What are 3 pros with RLE?
No need for cat surgery in future
Monofocal implants are available
Larger range of IOL powers are available
What are 3 cons with RLE?
Halo/Glare
loss of contrast sensisvitiy
Associated with vision threatening conditions
What are the name of the 3 tests done to test for ocular motility?
Hirschberg test
Krimsky test
Cover test
How does the Hirschberg test work?
What can it detect?
Using a pen light you note the corneal reflex and depending on the position depends on what kind of strabismus direction the px may have
Can detect strabismus in an infant but it is not a sensitive test
How does the Krimsky test work?
Using prism over the ‘normal eye’ will determine how much the other eye is deviating and in what direction. Depending on the amount of prism needed.
It is more accurate
How does the cover test work?
Reliable and easy
Cover one eye will the px is focusing ahead and the DR will note the movement in the other eye.
