Practical techniques for eye exams Flashcards
Schirmer tear test
60 seconds in the ventral conjunctival fornix between the lower lid and the third eyelid.
Do not touch the notched end with your fingers
If you like to fold, do it PRIOR to removing from the plastic package.
Always perform on BOTH eyes!
STT, species references..
Canine
18.84 +- 4.47
23.90 +- 5.12
21 +- 4.2
<10 = suspicious for KCS
<5- diagnostic for KCS
STT specie references..
Feline
14.3 +- 4.7
16.92 +- 5.73
Normal cats can have <5-10
Equine STT values
20.6 +- 6.5
24.8 +- 4.8
<10 = diagnostic for KCS
Explain the purpose of the STT.
?
Name the medical condition associated with an abnormally LOW STT
Research appropriate medical management options for the condition.
Recognize appropriate surgical management options for the condition including advantages and disadvantages of the procedure.
Review risk factors for the development of the condition.
Fluorescein test
Technique
- Fluorescein is a water-soluble, ophthalmic dye that is typically impregnated into sterile strips.
- Moisten a strip with a drop of sterile saline
- Allow a drop of dye to then fall upon each eye. In the event that you need to touch the strip to the eye, touch the strip to the sclera so that you do not artificially create what appears to be an area of fluorescein uptake on the surface of the cornea
- Now flush the eye gently with eye wash so as to rinse off the excess.
- If the cornea is intact, the dye will not stick.
- If the cornea is damaged, the fluorescein will adhere to the stromal layer.
- Observing fluorescein uptake is enhanced by using a blue light – either a Wood’s lamp or a filter on your standard direct ophthalmoscope.
- Note: Descemet’s membrane does not uptake fluorescein. Therefore, a clear area at the base of a deep defect in the cornea is a bad sign: it means that the ulcer is deep and in danger of rupturing.
Alternative flur. stain method..
Note: An alternate approach to fluorescein staining is to place the fluorescein strip in a 3cc syringe that is capped at the needle end. You then add sterile saline to the syringe, replace the plunger, and give a gentle shake to the syringe to create a slurry of dye that can then be squirted onto the each eye after the needle has been removed from the syringe.
ID…
desemetocele
Appreciate what a normal fundus looks like for both a dog and cat:
practical techniques paper
Feline fundus - normal-
practical techniques paper
What are the four structures you can ID when performing a fundic exam?
- optic disc
- retina
- tapetum
- retinal and choroidal vasculature
Identify what category of ophthalmic drugs you could use to facilitate the fundic examination by inducing pupillary dilation. Name two drugs that fit into this category, and be able to classify each as either short-acting or long-acting
Category of Ophthalmic Drug: Mydriatics
Two Types of Drugs in this Category:
o Atropine sulfate 1% (long-acting)
o Tropicamide 0.5% or 1% (short-acting)
The more negative (red) the diopter setting
the more DIVERGING power the lens possesses, and you are able to focus more posterior / caudally
The more positive (green) the diopter setting
the more CONVERGING power the lens possesses, and you are able to focus more anterior / cranially