VSR 421: Regional Veterinary Surgery (2+1)

Corneal ulcer

CORNERAL ULCER

• Fluorescein dye test positive corneal ulcer viewed through the cobalt filter of ophthalmoscope. The green colour in the center of the cornea indicates stain uptake by the corneal stroma.

Cornea ulcer

• Ulcerative keratitis is frequently met within animals.

Etiology

• The causes may be trauma, infections (like distemper in dogs), or nutritional deficiencies (like vitamin A deficiency and Riboflavin deficiency).

Symptoms

• The ulcer on the cornea is easily recognized. If necessary, a 2% flurorescein solution may be used to aid diagnosis. The solution is instilled into the eye so as to stain the ulcer and make it visible.

Prognosis

• Guarded and depends on how deep the ulcer is. depe When the ulcer heals a localized opacity of cornea results, because of the scar tissue.

Diagnosis

Diagnostic kit

Fluorescein dye test

• Impregnated paper strips moistened with saline
• Placed in dorsal bulbar conjunctiva
• Excess stain is washed with normal saline

Fluorescein dye test	Positive for Fluoresein dye test

 

Complications

• Keratocele: Protrusion of an intact decemet’s membrane through the ulcer is called keratocele. Keretocele may rupture. The rupture might help correction of the keratocele and the ulcer might heal up, if small. Rupture may predispose to prolapse of iris if the wound on the cornea is sufficiently large. So it is better to make a small puncture of the keratocele artificially to let out the aqueous humour and facilitate collapse of the protruded portion. The keratocentesis may be repeated, if necessary.
• Staphyloma: It is a protrusion of iris through a wound or ulcer on the cornea. There is leakage of aqueous humour and there is also chance of infection being carried through the perforation of the cornea. If the opening is large the lens may also prolapse. A small staphyloma resulting from a narrow opening in the cornea may slough off during the healing of the corneal wound.

Treatment of corneal ulcers

• Surgical treatment
  • temporory tarsorrhaphy
  • third eyelid flap
  • conjunctival flap
  • direct corneal suturing
  • therapuetic contact lenses
  • collagen grafting
• In addition to the surgical treatment, medical therapy is also indicated, which include topical antibiotics, collagenase inhibitors, atropine to prevent ciliary spasm, ocular lubricants, and systemic corticosteroids.