Diseases of the Cornea

What is pannus?

Chronic superficial keratitis

What is the signalment for pannus?

German Shepherds

Greyhounds

Dobermans

Where does pigment and vascularization start with pannus?

laterally

Where is pannus usually?

Higher altitudes

What is the hallmark for pannus?

Nonpainful pigment that starts laterally in german shepherds

Where is atypical pannus?

Third eyelid

How do you treat pannus?

Lifelong and aggressive initially with topical steroids and topical cyclosporine A or tacrolimus after it is undercontrol

What steroid should you use for Pannus treatment?

Prednisolone acetate is best

What is the signalment for pigmentary keratitis?

Pugs

Describe a pigmentary keratitis persentation?

Nonpainful leading to blinding, starts medially

What are the causes of pigmentary keratitis?

Multifactorial due to exposure, medial entropion, trichiasis

How do you treat pigmentary keratitis surgery?

Done in young patients with a medial canthoplasty

How do you treat pigmentary keratitis medically?

Topical cyclosporine or tacrolimus in mild cases

What breed should not get topical steroids on the eye?

Pugs

Where is the location of corneal dystophy?

Axial or paraxial

Describe corneal dystrophy

Inherited and bilateral opacity that is common and nonpainful

What causes the opacity during corneal dystrophy?

Lipid deposition

How do you treat corneal dystrophy?

None

What does corneal endothelial dystrophy cause?

Corneal edema

What breeds are predisposed to corneal endothelial dystrophy?

Boston terriers, boxers, dachshunds, poodles, chihuahuas that are young

How do you treat corneal endothelial dystrophy?

NaCl ointment 5%

Topical antibiotics for ulcers

Referral surgical procedures

What does corneal endothelial degeneration cause?

Corneal edema and bulla formation

What animals get corneal endothelial degerenation?

Old dogs

How do you treat corneal endothelial degeneration?

NaCl ointment 5%

Topical antibiotics for ulcers

Referral surgical procedures

What should all patients with corneal edema get?

STT, fluorescein dye, IOP

What is the most common corneal foreign body?

Plant material

How do you treat a superficial corneal foreign body?

Irrigation or cotton swab

What do you treat a deep corneal foreign body?

Referral for surgical removal

What are the C/S of corneal ulcers?

Blepharospasm, Rubbing, Epiphora, Elevated third eyelid, Red eye, Reflex uveitis

How do you diagnose a corneal ulcer?

Examine eyelids and conjunctiva, palpebral reflex, STT, fluorescein staining, examine posterior TEL, cytology and culture if infected

What is a STT?

Schirmer tear test

What can corneal blood vessels tell you?

If it is superficial or deep corneal ulcer

How long does it take for corneal bloodvessels to grow?

3-5 days

Superficial vessels

Deep vessels

What is a superficial corneal ulcer?

Only the cornea and visible with fluorescein stain only

What is the only corneal ulcer that is not visible with the naked eye?

Superficial

Superficial corneal ulcer

Desmetocele ulcer, middle is descemes membrane that is not stained cause it is so deep

What are the signs of an infected corneal ulcer?

Depth, corneal malacia, cellular infiltrate, pain, purulent ocular discharge, hypopyon, ciliary flush

What is corneal malcaia?

Melting of the cornea

How can you tell if an ulcer perforated?

Bulging due to fibrin, blood, iris, hyphema

When handling a patient with a perforated ulcer what do you need to do?

Retrain very gently

What can cause corneal ulcers?

Trauma, KCS, eyelash disorders, eyelid disorders, exposure, foreign body, infectious causes

Ulcer in the purple

Ectopic cilia

Ulcer in the green

KCS or exposure

Ulcer in the blue

Entropino

Ulcer in the red

Foreign body behind third eyelid

When do you need to surgically manage an ulcer?

If depth is greater than 50% or there is severe infection

Why do you never do a third eyelid flap?

it only covers the cornea and prevents you from observing the ulcer

How do you treat a superficial noninfected ulcer?

Broad spectrum antibiotics T-QID and mydriatic therapy (atropine)

Analgesics (systemic steroids or NSAIDS)

E-collar

What is should you never use on corneal ulcers?

Topical steroids or topical nonsteroidal anti inflammatories

Why do you not use topical steroids on corneal ulcers?

Delays corneal wound healing

Predispose to infection

Potentiate enzymatic destruction of the cornea

When do you recheck a superficial noninfected ulcer?

5-7 days

If a superficial noninfected ulcer has not healed in 5-7 days, what do you need to do?

Change the diagnosis and look for an underlying cause, infection, or an indolent ulcer

How do you treat an infected ulcer?

Antimicrobials based on culture q 1-2 hours until infection resolves

If you have an infected ulcer that has cocci on cytology what should you treat with?

Cefazolin 5%, chloramphenicol

If you have an infected ulcer that has rods what should you treat with?

Ofloxacin, gentamicin, tobramycin

Why do you not use petrolatum ointments to treat deep ulcers or ulcers with a chance for perforation?

The jelly can irritate the eye. Use drops instead

What do anti collagenase agents do?

They can decrease stromal melting during a corneal ulcer

What is the main anti collagenase agent you will use to prevent stromal melting?

Serum or plasma

What are some oral antibiotics that can be good for infected ulcers?

Clavamox or enrofloxacin

What should every infected ulcer patient get?

E collar and restrict activity

What in an indolent ulcer?

An ulcer that will not want to heal

What is the signalment for an indolent ulcer?

Boxers

What is SCCED?

Indolent ulcer or spontaneous chronic corneal epithelial defect

How do you identify an indolent ulcer?

Epithelial lip that is loose causing fluorescein leaking

How do you treat an indolent ulcer?

Surgery to remove the loose epithelium with a cotton tip

Or a grid keratotomy

Describe the surgery to treat an indolent ulcer

Use a topical anesthetic debride with a sterile cotton tipped applicator to remove all of the epithelium

What species should not get a grid keratotomy for an indolent ulcer?

Cats