Complicated corneal ulcer: Avoiding disasters (Proceedings)


Complicated corneal ulcer: Avoiding disasters (Proceedings)

Aug 01, 2008

Corneal Anatomy

1. Corneal erosion: Superficial: Epithelium

2. Corneal ulcer: Middle: Stroma

3. Descemetocoele: Deep: Endothelium and Descemet's membrane

Most Corneal Ulcers Occur for a Reason

1. Abnormal tear film

2. Abnormal blink motion

3. Decreased corneal sensation

4. Abnormal hairs

5. Inflammation

6. Immune-mediated

7. Degenerative

The primary goal in treating a corneal ulcer is to identify its cause or identify factors that may prevent it from healing well. Therefore a thorough ocular examination should be performed on any patient with an ulcer.

1. Eyelids:

a. Distichia- breed predisposition

b. Ectopic cilia- young dogs, very painful, dorsal erosion

c. Trichiasis- entropion

d. Meibomitis?

2. Conjunctiva

a. Follicles

3. Cornea

a. ulcer depth

b. ulcer character (malacic, infected, indolent)

4. Anterior chamber

a. uveitis (primary or reflex?)

5. Iris

a. Miosis

b. iritis

6. Lens

a. pathology?

7. Posterior segment

a. abnormalities?

Ophthalmic Tests

1. Schirmer Tear Test

a. Normal 15-25, but brachycephalic?

2. fluorescien stain

a. Stains stroma only, will delineate ulcer size

b. TFBUT >20 seconds

c. Undermining epithelial lip?

3. Tonometry

a. Ulcers can commonly occur secondary to rubbing from glaucoma discomfort.

Ulcer Management

1. Treat the underlying cause.

- Surgery for hair removal

- Tear stimulant therapy

- Glaucoma therapy

2. Manage concurrent problems.

- Systemic antibiotics

- Systemic anti-inflammatories

3. Choose antibiotic therapy based on severity of ulcer and predisposition to get worse.

- Triple antibiotic or Gentocin good first line defense

- Tobramycin for pseudomonas infections

- Tobramycin AND Ofloxacin for complicated ulcers

- Plasma for malacic ulcers

4. Consider supportive care.

- Tear replacement therapy

5. Determine if depth warrants surgical correction. (>50% consider)

- Conjunctival pedicle graft

- Cornealconjunctival transposition

- Island graft

- Artificial membrane tissue graft