Ophtho3- Equine

• pain
• photophobia
• blepharoedema
• miosis
• aqueous flare
• keratitic precipitates
• hypotony
• chorioretinitis

• synechia
• cataract
• phthisis bulbi
• corpora nigra atrophy
• peripapillary depigmentation ("class butterfly lesion" around the optic nerve)
• glaucoma
• retinal detachment
• blindness

apply fluorescein dye to eye to identify corneal leakage/ corneal lesions

• dilate pupil with tropicamide
• direct microscopy- gives you more magnification, can examine the optic nerve an retinal vessels
• +/- indirect microscopy- high level screening

• tonovet preferred- no anesthesia required
• if using tonopen, perform auriculopalpebral nerve block and topical anesthetic

• blocks retraction of globe and elevation of the third eyelid, blocks response to touch and visual stimuli
• used ophthalmic surgery for standing surgery,as an adjunct to general anesthesia, and to increase conal volume for enucleation

• blocks motor innervation to upper eyelid
• used to facilitate ophtho exam and when using tonopen to take IOP

• blocks sensory innervation to the upper eyelid
• used to facilitate ophtho exam

• Apaloosa
• seropositive for Lepto pomona

Immune-mediated: possibly brought on by [primary ocular] corneal ulceration, ocular trauma, lens-induced, primary ocular neoplasia, [systemic] septicemia (foals), viremia, parasitic, secondary neoplasia (LSA), immune-mediated ERU

• heat cycle
• deworming
• vaccination
• new horse introduced
• moved to a new barn
• horse show
• upper respiratory infection

glaucoma, ulcer, conjunctivitis (anything that causes red eyes)

• severity of uveitis, duration of episodes, response to treatment, and frequency of recurrence
• Increased risk of blindness in apaloosas and horses seropositive for Lepto pomona

• Non-specific therapy: topical or systemic corticosteroids/ NSAIDs (prednisone acetate, banamine), bute or aspirin for quiescent phase, atropine, suprachoroidal cyclosporin A (implant sustained release device)
• new technology- sustained release cyclosporin A intravitreal or subconjunctival
• Surgical: complete vitrectomy in Germany (in Lepto + patients)

synechiae, glaucoma, cataracts, retinal detachment, phthisis bulbi, blindness

secondary to anterior uveitis, especially associated with ERU

• Medical: timolol maleate (beta-blocker- decreases aqueous production), dorzolamide (topical CAI- decreases aqueous production)
• Surgical: acute cyclophotocoagulation (reduce aqueous production); chronic evisceration/ prosthesis or enucleation

paurangiotic retina (partially vascularized)- 30-60 small retinal vessels around the optic disc and the rest is avascular and suppled by the underlying choroidal vessels

• usually associated with neonatal septicemia and is sterile
• copious amounts of fibrin common
• intracameral tissue plasminogen activator used to clear fibrin

• glaucoma in the horse tends to cycle; pressures go up and go down; if the client calls you and you do get to the farm for 1-2 days, the signs may not be there anymore
• almost all glaucoma in horses is reversible; horses have more elasticity to the sclera, so when pressures go down, they eye goes back to normal size
• even with chronic glaucoma, horses rarely go blind from glaucoma

• band keratopathy is an idiopathic incidental finding
• cracks in descemets membrane (striae) from glaucoma are accompanied by other signs of glaucoma; they also exhibit more branching
• if you see a line across a horse’s cornea on a pre-purchase exam, take the horse’s pressures and look for signs of glaucoma and ERU

• is there a dazzle reflex
• is there consensual PLR
• what does ocular US look like

• #1 is ERU
• hereditary in foals
• sometimes traumatic

• surgery prior to 6 months; consider desired purpose of horse
• don't breed these animals

• glaucoma
• inflammation
• trauma
• ischemia
• compression