Equine Ophthalmology: Examination, Cornea, Eyelid Flashcards
Equine Ocular Anatomy
Lateral placement of eye - can see almost 360 degrees (blind spot small at tail ad nose)
top pic: Protruding black stuff is normal (UV protections)
Equine Eye Examination
where
nerves
anesthesia
Auricolpalpebral nerve block (stops blinking)
CCT = corneal touch threshold (never goes away, so never completely pain free)
Ophthalmic Examination (reflexes)
Position of the Eyelids
right pic: Abnormal cause lashes pointing down
Nasolacrimal flushing
Tonometry
Higher pressure than dogs/cats
Transillumination vs Retroillumination
left: Onto surface (cataract will look white)
right: Bouncing off tapetum (looks black)
all of these are normal
top left: Stars of winslow endonchoroidal vessels
Choiroidal vessels can be seen when no tapetum (normal!)
Poor angtiotic system so blood vessels only extend 1-2 mm from surface of optic disk, and none at 6 o clock position
Auriculopalpebral Nerve Block
Sensory Nerve Blocks
* Regions blocked
Sensory Nerve Blocks
what are they?
Squamous Cell Carcinoma (SCC)
importance
location
predisposing factors
SCC Treatment
But need to preserve function
SCC Progression
tattooing? NO, won’t prevent anything
Corneal Ulceration
common?
keys to success?
Corneal Ulceration Diagnosis
Superficial Ulcer Management
Dry eye is super rare in horses don’t usually worry about it
Complicated Corneal Ulcers
types
never assume indolent: Cause infected is way more common
Not finding fungus does NOT rule out fungal infection
Moat around and also white looking = fungus
Mila Subpalpebral Lavage Line
Subpalpebral Lavage Line
Complicated Corneal Ulcers
initial treatment
antibiotics
Very long therapy, 6-10 wk minimum
Complicated Corneal Ulcers
* Antifungal medications
Complicated Corneal Ulcers
* Antiproteinase/anticollagenase agents
* Oral NSAID
Complicated Corneal Ulcers
* Monitoring
* Surgical treatment
…
Corneal Stromal Abscess
Several weeks to form
Super painful
Corneal Stromal Abscess
* Medical treatment
These are the only ones that penetrate the cornea!
- Fluorquinolones
- Chloramphenicol
- Voriconazole, fluconazole…
Corneal Stromal Abscess
* Surgical treatment
Consider Referral If…
- Corneal stromal abscess
- Nonresponsive ulcers
- Infected ulcers
- Fungal hyphae discovered on cytology
- Ulcers >50% depth
- Ruptured ulcers