Flashcards in Equine Ophthalmology Deck (29)
Give some clinical signs of ulcerative keratitis
-Epiphora (excessive eye-watering)
What other stain can you use on the eye to check for ulcers?
Which part of the cornea is damaged with superficial ulcers?
Only the epithelium
How do you treat a superficial ulcer?
-Topical antimicrobials +/- topical atropine
-Healing rate= 0.6mm/day
Which part of the cornea is damaged with deeper ulcers?
What is keratomalacia?
What causes a melting ulcer?
Activation and/or production of proteolytic enzymes by:
-Corneal epithelial cells
-Microbial organisms (Pseudomonas)
Which bacteria is likely to be in an eye with a melting ulcer?
How do you treat keratomalacia (melting ulcers) and descemetoceles?
-Topical tetracyclines or doxycycline
-Systemic NSAIDs eg flunixin
What is a descemetacele?
-Melting ulcer that penetrates down to the Descemets membrane
-Will be fluoroscein-negative
How do you treat a stromal abscess?
-Antimicrobials (eg fluoroquinalones)
-May need surgery (debridement or corneal grafting)
What causes viral keratitis?
How would you recognise viral keratitis?
-Multiple superficial, white, punctate or linear opacities
-Varying degree of ocular pain
How do you diagnose viral keratitis?
Difficult: virus isolation +/- PCR
How do you treat viral keratitis?
-Topical Interferon γ
Are immune-mediated keratopathies usually unilateral or bilateral?
How do you treat an immune-mediated keratopathy?
-Medical: topical corticosteroid, cyclosporine A, doxycycline
-Surgical: keratectomy, cyclosporine A implant
What can happen if uveitis is left untreated?
What are the 2 ways anterior uveitis can occur?
-Primary (ie eye trauma)
-Secondary to systemic disease (eg Rhodococcus, Leptospira)
Give the clinical signs of anterior uveitis
-Pain: blepharospasm and epiphora
-Aqueous flare (milky appearance of anterior chamber)
-Blood, pus or fibrin in anterior chamber)
How do you treat uveitis?
-Topical corticosteroids (if no ulcer)
-Topical atropine (q 4 hours until pupil dilates)
-Topical NSAID (if ulcer)
-Topical antimicrobial? (if ulcer)
-Systemic NSAID (flunixin)
-Surgery: cyclosporine A implant, enucleation?
Give some long-term complications of uveitis
-Atrophy granula iridica
'Butterfly' lesions around the optic disc are associated with which condition?
What is the normal intraocular pressure of a horse?
Give some clinical signs of glaucoma
How do you medically treat glaucoma?
-Carbonic anhydrase inhibitors: topical (dorzolamide) and/or systemic (acetazolamide)
-Topical beta blockers: timolol
-Anti-inflammatories: NSAIDs and/or corticosteroids, topical and/or systemic
How do you surgically treat glaucoma?
-Laser destruction of ciliary body
95% of the retinal blood supply is provided by what?