Ophthalmology Practical Flashcards
What does a Schirmer Test measure?
Measures basal tearing and reflex e.g. in cases of Keratoconjunctivitis Sicca
What result indicates a healthy eye in the Schirmer Tear Test?
15mm of tears or higher
[less than= dry eye]
What is Fluorescein stain used for?
To stain corneal ulcers
How does Fluorescein work/ adhere to its layers?
epithelium & basement membrane are hydrophobic and underneath is the corneal stroma which is hydrophilic- the ulcer destroys the epithelium & basement allowing the stain to adhere to the hydrophilic stroma
What is the Seidal Test?
Uses fluorescein to determine if the cornea is penetrated and if there’s leakage of aqueous humour from the cornea ulcer
What does the Jones Test test for?
tests patency of nasolacrimal duct- test for blockages & epiphora (excessive tears)
What is the median transit time for the Jones Test in healthy dogs?
approx 4 mins
What is Ophthalmoscopy best used to view?
to view posterior segment and ocular fundus
What are the 3 main differences between direct and indirect ophthalmoscopy?
- indirect- can view a larger portion of the fundus
- indirect can be done from a larger & safer working distance from the patient
- indirect is an inverted and reversed view
What is a Rebound Tonometer?
small probe is propelled from a fixed distance to contact the cornea- eyes with higher IOP will have a shorter return time
What is a Application Tonometer?
measures the pressure required to flatten a constant area of the cornea
Which Tonometer requires local anaesthetic?
Application Tonometer
What is the normal IOP for a Dog and a Horse?
Dog- 10-20mmHg
Horse- 15-25mmHg
