Equine Ophthalmology: Examination, Cornea, Eyelid

Question 1

Equine Ocular Anatomy

Answer 1

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)

Question 2

Equine Eye Examination
where
nerves
anesthesia

Answer 2

Auricolpalpebral nerve block (stops blinking)

CCT = corneal touch threshold (never goes away, so never completely pain free)

Question 3

Ophthalmic Examination (reflexes)

Answer 3

Question 4

Position of the Eyelids

Answer 4

right pic: Abnormal cause lashes pointing down

Question 5

Nasolacrimal flushing

Answer 5

Question 6

Tonometry

Answer 6

Higher pressure than dogs/cats

Question 7

Transillumination vs Retroillumination

Answer 7

left: Onto surface (cataract will look white)
right: Bouncing off tapetum (looks black)

Question 8

Answer 8

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

Question 9

Auriculopalpebral Nerve Block

Answer 9

Question 10

Sensory Nerve Blocks
* Regions blocked

Answer 10

Question 11

Sensory Nerve Blocks
what are they?

Answer 11

Question 12

Squamous Cell Carcinoma (SCC)
importance
location
predisposing factors

Answer 12

Question 13

SCC Treatment

Answer 13

But need to preserve function

Question 14

SCC Progression

Answer 14

tattooing? NO, won’t prevent anything

Question 15

Corneal Ulceration
common?
keys to success?

Answer 15

Question 16

Corneal Ulceration Diagnosis

Answer 16

Question 17

Superficial Ulcer Management

Answer 17

Dry eye is super rare in horses don’t usually worry about it

Question 18

Complicated Corneal Ulcers
types

Answer 18

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

Question 19

Mila Subpalpebral Lavage Line

Answer 19

Question 20

Subpalpebral Lavage Line

Answer 20

Question 21

Complicated Corneal Ulcers
initial treatment
antibiotics

Answer 21

Very long therapy, 6-10 wk minimum

Question 22

Complicated Corneal Ulcers
* Antifungal medications

Answer 22

Question 23

Complicated Corneal Ulcers
* Antiproteinase/anticollagenase agents
* Oral NSAID

Answer 23

Question 24

Complicated Corneal Ulcers
* Monitoring
* Surgical treatment

Answer 24

Question 25

Answer 25

…

Question 26

Corneal Stromal Abscess

Answer 26

Several weeks to form
Super painful

Question 27

Corneal Stromal Abscess
* Medical treatment

Answer 27

These are the only ones that penetrate the cornea!
- Fluorquinolones
- Chloramphenicol
- Voriconazole, fluconazole…

Question 28

Corneal Stromal Abscess
* Surgical treatment

Answer 28

Question 29

Consider Referral If…

Answer 29

• Corneal stromal abscess
• Nonresponsive ulcers
• Infected ulcers
• Fungal hyphae discovered on cytology
• Ulcers >50% depth
• Ruptured ulcers