Corneal Disorders Flashcards
What are the layers of the equine cornea?
Epithelium, stroma, Descemet’s Membrane
What causes ulcerative keratitis?
Trauma, FB, Exposure/paralytic Keratitis, EHV, KCS
How does a corneal ulcer normally heal? How does a complicated ulcer heal?
Normal: Injury -> cell slide in -> mitosis -> normal epithelium
Complicated: Defect -> bacterial invasion -> tissue destruction -> corneal perforation
How do you categorize ulcers?
Superficial
Stromal (Superficial, mid, deep or melting)
Descemetocele
How do you diagnose ulcerative keratitis?
Eyelid block, underlying cause, culture, cytology and fluorescein stain
What can cause a complicated ulcer?
Bacterial, fungal stromal degradation, iridocyclitis
What kind of ulcers are emergency that go straight to surgery?
Melting or desmetocele
What is a pathoneumonic sign for a fungal infection of eye?
Clear ring/moat around the white material
What are the goals of therapy for ulcerative keratitis?
Control infection, inhibit corneal proteolysis, manage secondary uveitis, increase comfort
How do you medically manage ulcerative keratitis?
Antibacterial until healed - broad spectrum
Antifungals - Opthalmic preparation and dermatologic
Cycloplegia
Anti-inflammatory
Anti-protease (doxy, systemic, n-acetylcysteine, autologous serum)
Surgical- melting or desmetocele
What are other considerations you should have in mind when you have ulcerative keratitis?
FB, facial paresis, paralysis, KCS, non-healing ulcer
What causes corneal perforation? What are some forms it can take?
Trauma, infection
Laceration, fungal, iris melt, prolapse, hypopyon and hyphemia
When is corneal perforation a surgical disease?
Always
What do you do for a patient with a corneal ulcer that is waiting for surgery?
Topical and systemic antibiotics, topical antifungals, topical atropine, NSAID
What do you see when there is a corneal abscess?
Yellow-white stromal opacity, severe ocular discomfort, secondary uveitis
How do you manage a corneal abscess?
Antimicrobial
Secondary uveitis, vascularize
or
Surgical excision - faster, conjunctival flap and keratoplasty
What is band keratopathy?
Corneal mineralization and calcification
- degenerative condition in old age
Is band keratopathy painful?
No usually unless ulcerated
What is associated with band keratopathy?
ERU
What is IMMK?
Immune mediated keratitis
-Chronic, nonpainful, unilateral commonly
-immune reaction - loss corneal immune privilage
What are the 4 clinical classifications for IMMK?
Epithelial (white dots), superficial stromal (haze and vascularization), mid stromal(yellow), endothelial (corneal edema bad)
What are clinical signs of eosinophilic keratocnjuctivitis?
Ocular discomfort, raided pink and white corneal plaque, corneal ulceration
How do you treat IMMK?
Topical steroid or cyclosporine - lifelong
-not helpful if endothelial form
Surgical - lesion out or cyclosporine in with photodynamic therapy
How do you treat eosinophilic keratoconjunctivitis?
Topical steroid, systemic steroid, cyclosporine, antihistamine, keratectomy
