section name header

Basics ⬇

Outline

BASICS

Overview!!navigator!!

  • Ocular trauma may have possible effects on any ocular structure such that ocular injury can have a variety of manifestations
  • Blunt injuries carry a worse prognosis than injury from sharp objects as blunt forces are transmitted and often reverberate throughout the eye. Sharp, penetrating injuries generally have the forces localized to the site of impact

Signalment!!navigator!!

Any age and breed of horse may suffer corneal laceration.

Signs!!navigator!!

  • The eye may be cloudy, red, and painful. Blepharospasm and lacrimation are present with focal or generalized corneal edema. Slight ventral deviation of the eyelashes of the upper eyelid may be a subtle sign of corneal ulceration
  • Full-thickness corneal/scleral perforations are usually associated with iris prolapse, shallow anterior chamber, and hyphema. If the corneal lesion extends to the limbus, the sclera should also be carefully checked for perforation. Scleral wounds can be obscured by conjunctival chemosis and hemorrhage

Causes and Risk Factors!!navigator!!

Trauma from nails, buckets, light fixtures, vegetative material, and tree branches can result in corneal/scleral lacerations.

Diagnosis ⬆ ⬇

Outline

DIAGNOSIS

Differential Diagnosis!!navigator!!

Ocular pain may also be found with corneal ulcers, uveitis, conjunctivitis, glaucoma, blepharitis, and dacryocystitis.

CBC/Biochemistry/Urinalysis!!navigator!!

N/A

Other Laboratory Tests!!navigator!!

N/A

Imaging!!navigator!!

N/A

Other Diagnostic Procedures!!navigator!!

Fluorescein dye staining of the cornea will reveal the laceration. Fluorescein dye may enter the anterior chamber. Seidel's test may reveal leakage of aqueous humor from the anterior chamber through the corneal laceration.

Pathologic Findings!!navigator!!

N/A

Treatment ⬆ ⬇

TREATMENT

  • Medical therapy should be sufficient for superficial, nonperforating lacerations. Deep or irregular corneal lacerations require surgical repair and more aggressive therapy for iridocyclitis. Direct corneal suturing and conjunctival flaps are indicated to more rapidly restore corneal integrity
  • Both small and large full-thickness corneal perforations should be surgically repaired. Complications include infection, iris prolapse, anterior synechiae, cataract formation, and persistent iridocyclitis. Both small and large corneal or scleral full-thickness defects can result in phthisis bulbi if left untreated
  • An eye with a traumatic corneal perforation that defies repair, extensive extrusion of intraocular contents, severe intraocular hemorrhage, or evidence of infection should be enucleated

Medications ⬆ ⬇

Outline

MEDICATIONS

Drug(s) of Choice!!navigator!!

Medical therapy alone should be sufficient for superficial, nonperforating lacerations. Topically applied antibiotics (chloramphenicol, bacitracin–neomycin–polymyxin B, gentamicin; every 2–6 h), atropine (1%; QID), and serum (every 1–6 h) are recommended. Systemic NSAIDs (phenylbutazone 2 mg/kg BID PO; flunixin meglumine 1 mg/kg BID PO, IM, IV) and broad-spectrum parenteral antibiotics are also indicated for full-thickness lesions.

Contraindications/Possible Interactions!!navigator!!

Horses receiving topically administered atropine should be monitored for signs of colic.

Follow-up ⬆ ⬇

Outline

FOLLOW-UP

Patient Monitoring!!navigator!!

  • The horse should be protected from self-trauma with hard- or soft-cup hoods
  • Horses with corneal lacerations and secondary uveitis should be stall rested until the condition is healed. Intraocular hemorrhage and increased severity of uveitis are sequelae to overexertion
  • Diet should be consistent with the training and activity level of the horse

Prevention/Avoidance!!navigator!!

N/A

Possible Complications!!navigator!!

  • Failure to detect a scleral tear will result in chronic hypotony and globe atrophy (phthisis bulbi)
  • The eye of the horse does not tolerate much damage to its vasculature. Severe intraocular hemorrhage usually results in phthisis bulbi
  • Injury to the lens, iris, and retina can accompany blunt or sharp corneal/scleral trauma
  • Septic intrusion into the globe results in painful endophthalmitis. Such infection can spread to surrounding soft tissues and necessitates enucleation

Expected Course and Prognosis!!navigator!!

  • Small corneal lacerations can heal quickly if surgical and medical therapy is prompt. Larger lesions are associated with more uveitis and will be slower to heal
  • If the horse has a dazzle reflex in the damaged eye and a consensual pupillary light reflex in the fellow eye, then repair should be attempted

Miscellaneous ⬆ ⬇

Outline

MISCELLANEOUS

Associated Conditions!!navigator!!

Corneal lacerations in the horse are always accompanied by varying degrees of iridocyclitis.

Age-Related Factors!!navigator!!

N/A

Zoonotic Potential!!navigator!!

N/A

Pregnancy/Fertility/Breeding!!navigator!!

N/A

Abbreviations!!navigator!!

NSAID = nonsteroidal anti-inflammatory drug

Suggested Reading ⬆ ⬇

Brooks DE. Ophthalmology for the Equine Practitioner, 2e. Jackson, WY: Teton NewMedia, 2008.

Brooks DE, Matthews AG. Equine ophthalmology. In: Gelatt KN, ed. Veterinary Ophthalmology, 4e. Ames, IA: Blackwell, 2007:1165–1274.

Gilger BC, ed. Equine Ophthalmology, 3e. Philadelphia, PA: WB Saunders, 2017.

Author(s) ⬆

Author: Caryn E. Plummer

Consulting Editor: Caryn E. Plummer

Acknowledgment: The author/editor acknowledges the prior contribution of Dennis E. Brooks.