Cornea

Question 1

cornea (rankin)

Pannus

Answer 1

• Chronic superficial keratitis
• Most common
  
  • German Shepherds
  • Greyhounds
  • Dobermans
• Pigment and vascularization
  
  • Starts laterally
• Higher altitudes
• Bilateral disease
• NONPAINFUL!!!!!!
• Atypical pannus
  
  • Third eyelid
  • Depigmented and follicles

Question 2

cornea (rankin)

Pannus Treatment

Answer 2

• Life long treatment!!!!
• Treat aggressively initially then taper
• Topical steroids
  
  • Prednisolone acetate 1%
  • Neopolydex (0.1% dexamethasone)
  • 3-4 times daily
• Topical cyclosporine A or tacrolimus
  
  • 1or 2% CsA from licensed compounding pharmacy
  • 0.2% CsA Optimmune ®
  • 0.02% 0.03% tacrolimus from licensed compounding pharmacy
  • BID
• Taper medications
  
  • Control with CSA or tacrolimus

Question 3

Pigmentary Keratitis

Answer 3

• PUGS!!!!
  
  • 82.4%
• Nonpainful
  
  • Blinding
• Starts medially
• Multifactorial
  
  • Exposure
  • Medial entropion
  • Trichiasis

Question 4

Treatment of Pigmentary Keratitis

Answer 4

• Surgical
  
  • Medial canthoplasty
• Medical therapy
  
  • Mild cases
  • Topical cyclosporine or tacrolimus (SID to BID)
  • Avoid topical steroids in PUGS!!!

Question 5

Corneal Dystrophy

Answer 5

• Opacity
  
  • Axial or paraxial
• Inherited, bilateral
• Relatively common
• Nonpainful
• Lipid deposition
• No treatment

Question 6

Corneal Endothelial Dystrophy

Answer 6

• Corneal edema
• Inherited
  
  • Boston Terriers, Boxers, Dachshunds, Poodles, and Chihuahuas
• Generally young dogs
• Treatment:
  
  • NaCl ointment 5% T-QID
    
    • Muro128
  • Topical antibiotics for ulcers
  • Referral surgical procedures

Question 7

Corneal Endothelial Degeneration

Answer 7

• Corneal edema
• Bulla formation
  
  • Recurrent ulcerations
• Old dog disease
• Treatment
  
  • NaCl ointment 5% T-QID
    
    • Muro 128
  • Topical antibiotics for ulcers
  • Referral surgical procedures

Question 8

Corneal Foreign Body

Answer 8

rare in cats

Question 9

cornea (rankin)

Corneal Ulcers

• Clinical signs

Answer 9

• Blepharospasm
• Rubbing
• Epiphora
• Elevated third eyelid
  
  • “Red
  • Reflex uveitis
    
    • Miosis , aqueous flare, hypopyon, fibrin, photophobia

Question 10

cornea (rankin)

Diagnosis of Corneal Ulcer

Answer 10

• Examine eyelids and conjunctiva
• Palpebral reflex
• STT
• Fluorescein staining
• Examine posterior TEL
• Cytology
• Culture and sensitivity

Question 11

cornea (rankin)

Corneal Ulcer

• superficial vs deep

Answer 11

• Corneal blood vessels
  
  • 3-5 days to begin to grow
  • ~1mm/day
• Is it superficial or deep?

Question 12

cornea (rankin)

Infected Corneal Ulcer Signs

Answer 12

• Depth
• Corneal malacia
• Cellular infiltrate
• Pain
• Purulent ocular discharge
• Hypopyon

Question 13

Has the ulcer perforated?

Answer 13

• Perforation site will be “bulging”
• Sealed with
  
  • Fibrin
  • Blood
  • Iris
• Hyphema
• Shallow anterior chamber
• Restrain patient “VERY GENTLY”

Question 14

Causes of ulcers

Answer 14

• Trauma
• KCS
• Eyelash disorders (ectopic cilia/rarely distichiasis)
• Eyelid disorders (entropion)
• Exposure (lubricate under general anesthesia!!!)
• Foreign body
• Infectious causes (herpesvirus and Moraxella Bovis

Question 15

cornea (rankin)

How am I going to manage the ulcer?

Answer 15

• If greater than 50% depth or severe infection:
  
  • Surgical therapy recommended: Conjunctival graft, corneoconjunctival transposition, corneal transplant, amnionic memebrane graft referral

Question 16

cornea (rankin)

Surgical Therapy for Ulcers

Answer 16

Do NOT place a third eyelid flap…it only covers up the cornea and prevents you from observing the ulcer…

Question 17

cornea (rankin)

Superficial NON-infected Ulcer

• meds

Answer 17

• Broad spectrum antibiotic
  
  • Neomycin/bacitracin/polymyxin B ointment
    Neomycin/bacitracin/ gramacidin solution
  • Tobramycin ophthalmic solution
  • Treat T-QID
• Mydriatic therapy
  
  • Treat “reflex uveitis”
  • Topical 1% atropine (SID or BID)
  • Do not use if decreased tear production or glaucoma
• Drops vs. ointment?
  
  • Hypersalivation (especially in cats)
• Analgesic/anti-inflammatory therapy
  
  • DO NOT EVER USE TOPICAL STEROIDS OR TOPICAL NONSTEROIDAL MEDICATIONS
    
    • Delay corneal wound healing
    • Predispose to infection
    • Potentiate enzymatic destruction of the cornea
  • Systemic NSAIDS
• Analgesic therapy
  
  • Codeine
  • Tramadol
• Prevent self trauma
  
  • Elizabethan collar!!!!

Question 18

cornea (rankin)

Superficial NON-infected Ulcer

• after treatment?

Answer 18

• Recheck in 5 7 days
• If the ulcer has not healed
  
  • Change the diagnosis…not the antibiotic!!!
• If the ulcer has not resolved
  
  • Underlying cause
  • Ulcer is infected
  • Indolent ulcer

Question 19

cornea (rankin)

Treatment of Infected Ulcers

Answer 19

• Antimicrobials - based on culture/sensitivity
• Antimicrobials - based on cytology
  
  • Cocci - cefazolin 5%,chloramphenicol
  • Rods - ofloxacin, gentamicin, tobramycin
• Use q 1-2 hrs initially and decrease as infection resolves
• Use drops if the ulcer is deep or if perforation is a possibility…the petrolatum vehicle in ointments causes severe inflammation inside the eye
• Anticollagenase agents
  
  • Decrease stromal melting
  • Serum/plasma
    
    • Autologous/ homogolous /heterologous
    • Treat q 1-2 hrs initially
    • Keep refrigerated for up to 2 weeks
  • Others: EDTA, N-acetylcysteine , ilmostat , tetracycline antibiotics
• Topical atropine1% SID or BID
• Oral antibiotics
  
  • Clavamox or enrofloxacin
• Oral anti-inflammatory/analgesics
• ELIZABETHAN COLLAR AND RESTRICT ACTIVITY!
• Recheck in 24 hours

Question 20

cornea (rankin)

Indolent Ulcer/SCCED

Answer 20

• Spontaneous chronic corneal epithelial defect
• BOXERS
• Middle/older age dogs
• Chronic
• Epithelial lip
• Fluorescein ‘leaking’

Question 21

cornea (rankin)

Surgical Treatment of Indolent Ulcers

Answer 21

• Remove loose epithelium
  
  • Topical anesthetic
  • Dilute providone-iodine soln.
  • Sterile eyewash
  • Debride with sterile cotton tipped applicator
  • ~4 0% will heal
  • Need to remove ALL loose epithelium
  • Usually need to go several millimeters past fluorescein positive area
• Grid / diamond burr keratotomy (NOT IN CATS)
  
  • ~85 90% success rate

Question 22

cornea (rankin)

Indolent Ulcers

• meds

Answer 22

• Topical broad spectrum antibiotic T QID
• Topical atropine 1% (SID to BID)
• Elizabethan collar
• Oral analgesics/NSAIDS if needed