Dealing with non straightforward superficial ulcers in dogs

Roxy Rodriguez, DVM, MS

Email: rrodriguez@vt.edu

Cornea

Normally avascular

Average thickness: 0.5 mm

Tear film

Corneal epithelium

StromaCollagen fibrils, keratocytes, nerves and GAGs

Descemet’s membraneBasement membrane for endothelial cells

Corneal endothelial cells

What is a “straight forward” uncomplicated ulcer?Superficial (lack of corneal epithelium) ulcer that resolves in 3-5 days.

When faced with an ulcer, always ask yourself…

What’s the underlying cause?Depth: superficial or stromal?Complicated or uncomplicated?

Underlying causes Distichia

Ectopic cilia Trichiasis

Corneal foreign bodyExposure keratitis

Exposure keratitis Exposure keratitis

KCSExophthalmiaBuphthalmiaParalytic (facial nerve paralysis)Macroblepharon

Calcium/lipid deposit Endothelial dystrophy/degeneration

Endothelial dystrophy/degenerationLook behind eyelids and third eyelids!

More foreign bodies!

How deep is the ulcer?

Depth

Depth: superficial Depth: stromal

Depth: descemetocele, perforation

Is it complicated or uncomplicated?

Uncomplicated vs. complicated

UncomplicatedSuperficial

None (or very faint)

None

None

ComplicatedAffects the

stroma

Edema

Cellular infiltrate/melting

Severe anterior uveitis

Superficial uncomplicated ulcer

No cellular infiltrateNo corneal edemaNo severe reflex uveitis

Uncomplicated corneal ulcer

Search and eliminate causeTopical broad spectrum antibiotics

**To prevent infection+/- CycloplegicsLubricationRecheck in 3-5 days

Uncomplicated ulcers

To control conjunctival flora to PREVENT problems

Neomycin Gram +/-Polymyxin B Gram –

BacitracinGramicidin

Gram +

What about SCCEDs?

SCCEDs

Spontaneous chronic cornealepithelial defect

Fails to resolve through normal would healingBreeds:

BOXER!Labrador, Golden, Bulldog, etc.

SCCEDs

Physiology: why don’t they heal?Epithelium dysmaturates poorly adhering to stromaBasement membrane and adhesion complexes are absentThin superficial hyalinized acellular stromal zone

SCCEDs

Treatment optionsGrid or punctate keratotomyDiamond burr debridementKeratectomy

Bandage contact lens?

Diamond burr debridement

Purpose:Removes nonadherent epitheliumRemoved abnormal adhesion complexesRemoves hyalinized zone

Contraindications:Complicated ulcers (stromal loss, signs of infection, etc.)Infectious keratitis

Bandage contact lens

Contraindications:Complicated ulcers (stromal loss, signs of infection, etc.)Infectious keratitis

Common conundrums

Switch antibiotics?

Not unless it is now complicatedCheck cytology/culture

Triple AB is NOT going to cut it

Choose flourquinolones or aminoglycoside/cephalosporin combo

Add serum/plasma?

Will not harm but may not be needed

Only required/recommendedComplicated ulcers

Stromal

Descemetoceles

Superficial infected ulcers

SCCEDs?* serum maybe

Recommend freezing serum/plasma from donor dogsCan use cross-species (*short term)

Debride?

ONLY if a SCCED

NOT:Stromal ulcers

Descemetoceles

Superficial complicated ulcers

If SCCED was debrided in last 10 days

Remend?

Remend® 0.75%

Corneal Repair Gel uses cross-linked, modified hyaluronic acid (HA) to help support the natural healing process of superficial corneal ulcerations of dogs and cats.

Must use antibiotic (*if for ulcer)Still treat underlying cause

www.petmartpharmacy.com

www.petrxdirect.comCan not use alone!

Summary

If not healed within 3-5 days:Revisit the drawing board!

Causes?Depth?Now complicated?SCCED?

Questions?