Cornea & Sclera Flashcards
What is Pannus
- Chronic superficial keratitis
- Common in:
- German shepherds, greyhounds, dobermans
- Bilateral disease
- pigment and vascularization starts laterally
- Non-painful
- More common at higher altitudes (Mountains)
What is atypical pannus?
- Affecting 3rd eyelid
- Depigmentation and follicles
What is the treatment for Pannus?
- Life long treatment
- Initially aggressive then tapers
-
Topical steroids
- Prednisolone acetate 1%
- Neopolydex (0.1% dexamethasone)
- 3-4x daily
-
Topical cyclosporine A or Tacrolimus
- 1 or 2% CsA from licensed compounding pharmacy
- 0.2% CsA Optimmune®
- 0.02% - 0.03% tacrolimus from licensed compounding pharmacy
- BID
- Taper medications - control w/ CsA or Tacrolimus
What is Pigmentary keratitis?
- Non-painful but blinding
- Starts medially
- Multifactorial
- Exposure
- Medial entropion
- Trichiasis
- Common in Pugs - 82.4%
What is the treatment for Pigmentary Keratitis?
- Surgical
- medical canthoplasty
- Medical Therapy
- mild cases
- Topical cyclosporine or tacrolimus (SID to BID)
- Avoid topical steroids in Pugs
What is Corneal Dystrophy?
- Inherited, bilateral disease
- Opacity in cornea - lipid deposition
- axial or paraxial
- Relatively common
- Non-painful
- No treatment
What is Corneal Endothelial Dystrophy? Treatment?
- Corneal Edema
- Genetic - Boston Terriers, Boxers, Dachshunds, Poodles, Chihuahuas
- Young dog disease
- Treatment
- NaCl Ointment 5% TID to QID
- Muro128
- Topical antibiotics for ulcers
- Referral surgical procedures
- NaCl Ointment 5% TID to QID
What is Corneal Endothelial Degeneration? Treatment?
- Corneal Edema
- Bulla Formation w/ recurrent ulcerations
- Old dog disease
- Treatment:
- NaCl ointment 5% TID to QID
- Muro128
- Topical antibiotics for ulcers
- Referral surgical procedures
- NaCl ointment 5% TID to QID
What is the treatment for Corneal Foreign Bodies?
- Superficial - Irrigation or cotton swab
- Deep - Referral for surgical removal
What are the clinical signs of Corneal Ulcers?
- Blephorospasm
- Rubbing
- Epiphora
- Elevated Third eyelid
- “Red eye”
- Reflex uveitis
- Miosis, aqueous flare, hypopyon, fibrin, photophobia
How are Corneal Ulcers diagnosed?
- Examine eyelids and conjunctiva
- Palpebral reflex
- STT
- Fluorescein staining
- Examine posterior TEL
- Cytology
- Culture and sensitivity
What are the signs of infected corneal ulcers?
- Depth
- Corneal malacia
- Cellular infiltrate
- Pain
- Purulent ocular discharge
- Hypopyon (accumulation of leukocytes in the anterior chamber of the eye)
What happens when a corneal ulcer perforates?
- Perforation site will “bulge”
- Sealed with Fibrin, Blood, Iris
- Hyphema (accumulation of blood in the anterior chamber of the eye)
- Shallow anterior chamber
What causes ulcers?
- Trauma
- KCS
- Eyelash disorders (extopic cilia/rarely distichiasis)
- Eyelid disorders (entropion)
- Exposure (lubricate under general anesthesia)
- Foreign body
- Infectious causes (herpesvirus and Moraxella Bovis)
- Location can suggest cause
What is the recommendation for ulcers greater than 50% in depth or severe infection?
- Surgical therapy:
- Conjunctival graft
- Corneoconjunctival transposition
- corneal transplant
- amniotic membrane graft (referral)
What surgical therapy is not recommended for ulcers?
- Do not place 3rd eyelid flap
- covers cornea
- prevents observation of the ulcer
What is the recommendation for superficial non-infected ulcers?
- Broad spectrum antibiotic
- Neomycin/bacitracin/polymyxin B ointment
- Neomycin/bacitracin/gramacidin solution
- Tobramycin ophthalmic solution
- Treat TID to QID
- Mydriatic therapy
- Treat “reflex uveitis”
- Topical 1% atropine (SID to BID)
- Do not use if decreased tear production or glaucoma
- Analgesic/anti-inflammatory Therapy
- Never use topical steroids or topical nonsteroidal medications
- Systemic NSAIDS
- Analgesic therapy
- Codeine
- Tramadol
- Prevent self trauma
Why are topical analgesic/anti-inflammatory treatments not used on eyes with corneal ulcers?
- Delay corneal wound healing
- Predispose to infection
- Potentiate enzymatic destruction of the cornea
What should be done if a superficial non-infected ulcer is still present at a 5-7 day recheck?
- If ulcer is not healed - change the diagnosis, not antibiotic
- If ulcer has not resolved:
- Underlying cause not addressed
- Ulcer is infected
- Indolent ulcer
What is the treatment for Infected corneal ulcers?
-
Antimicrobials:
- Based on Culture/sensitivity
- Based on cytology
- Cocci - cefazolin 5%, chloramphenicol
- Rods - ofloxacin, gentamicin, tobramycin
- Use every 1-2 hrs initially and decrease as infection resolves
- Use drops for deep ulcers, or in ulcers where perforation is a possibility
-
Anticollagenase agents
- decrease stromal melting
- Serum/plasma
- Autologous/homogolous/heterologous
- Treat q1-2 hrs initially
- Keep refrigerated for up to 2wks
- Others: EDTA, N-acetylcysteine, ilmostat, tetracycline antibiotics
- Topical Atropine 1% SID or BID
- Oral Antibiotics - Clavamox or Enrofloxacin
- Oral anti-inflammatory/analgesics
- E-collar and restrict activity
- Recheck in 24hrs
Why should eye drops be used for deep ulcers, or in ulcers where perforation is a possibility?
Petrolatum vehicle in eye ointments causes severe inflammation inside the eye
What is a Spontaneous Chronic Corneal Epithelial Defect (SCCED)?
- Indolent ulcer
- Chronic
- has epithelial lip
- Fluorescein is “leaking”
- Affects Middle/older aged dogs
- Common in Boxers
What is the surgical treatment options for Indolent Ulcers
- Remove loose epithelium
- Topical anesthetic
- Dilute providone-iodiine solution
- Sterile eyewash
- Debride w/ sterile cotton tipped applicator
- remove ALL loose epithelium
- usually need to go several mm past fluorescein positive area
- ~40% will heal
- Grid/Diamond burr keratotomy
- ~85-90% success
- Do not do in cats
What is the treatment for indolent ulcers outside of surgery?
- Topical broad spectrum antibiotic TID to QID
- Topical atropine 1% (SID to BID)
- E-collar
- Oral analgesics/NSAIDS if needed
