Supplemental 4% Flashcards
Normal axial length…
23.5mm
Range is 22.0mm-24.5mm
Normal AC Depth
3.24mm (varies esp with GLC pts)
Normal lens thickness
4.63mm-6.9mm (thicker as it becomes cataractous)
Normal K readings
43.0mm-44.0mm (usually withing 1D of the fellow eye)
Normal CCT (Central corneal thickness)
555mcm
Thicker the K thickness the ____
higher the IOP reading will be(real IOP lower)
Thinner the CCT…
the lower the IOP reading (actual IOP higher)
What test measures CCT?
corneal pachymetry
The goldmann tonometer was calibrated for an _____ CCT
average
Pachy also used pre and post operative refractive sx because…
if K is thin they may not be a candidate for refractive sx
Which test measures the tears using strips of filter paper.
Schirmer’s
Which Schirmer’s test measures lacrimal gland output and does not use any topical anesthetic
Schirmer’s I
Where do you place the filter paper strip when performing Schirmer’s test
on LL’s temporally to K to prevent K abrasion
How long do you leave the Schirmer’s strip in with pt eyes closed?
5 minutes(no blinking or squeezing)
Schirmer’s test that uses a topical anesthetic.
Schirmer’s II
What is the normal range for tears on the Schirmer’s test?
10-30mm
What is the dry eye range measurement on the Schirmer’s test?
<10mm
What is the Excess Lacrimation range on the Schirmer’s test?
> 30mm
What is the test that evaluates Dry Eyes with topical fluorescein dye?
TBUT (tear break up time)
How is TBUT performed?
Fluorescein is instilled and they eye is observed through the slit lamp, ask pt to close their eyes then open. When they open their eyes start timer and watch eye for tear film break up. When dry spots first appear, stop timer- this is their tear break up time. The shorter the TBUT the dryer the eye.
Drop that stains, highlights degenerating corneal and conj cells.
Rose bengal
Rose Bengal used for pts with….
Dry eyes, K abrasions, K lesions, (it stings)
Drop used to evaluate dry eyes, stains blue, does not sting, and stains muco-deficient patches (speckling of K indicates dry patches, muco-deficient or damaged K cells)
Lissamine Green
Uses a device that has a single use microchip and a docking device that analyzes the results of a tear measurement. It is objective and reliable.
Tear Osmolarity Testing
Explain how to perform Tear Osmolarity Testing
First you take a small sample taken of inferior-lateral meniscus, then dock with the device that analyzes it.
What are the ranges of results for Tear Osmolarity Testing?
Dry eye: greater than or equal to 316 mOsmol/L(Hyperosmolarity)
Borderline: 290 mOsmol/L to 316 mOsmol/L
Normal: less than or equal to 290 mOsmol/L
Glare testing is performed with…
BAT(Brightness acuity tester)
This test estimates level of functional outdoor vision like noon day sun, oncoming headlights, light reflected off of sand or snow.
BAT
What pts would you perform BAT on?
pt with CAT
and PCO
You perform BAT test with pt glasses____
on
How do you perform BAT?
Have pt leave glasses on, occlude one eye, have pt hold BAT in front of eye being tested, have them look at the eye chart through the little hole and have them read it.
How big is the hole in the BAT?
12mm
A book of pseudoisochromatic color plates that have numbers, symbols, or patterns that tests for color vision
Ishihara
In the Ishihara, there is a control plate in the beginning of book that ___pts can see, even with no color perception.
All