Superficial Non-Healing Ulcers

Outline

Overview
Signalment
Signs
Causes and Risk Factors

BASICS

Overview

Superficial non-healing or refractory ulcers are injuries of the corneal epithelium that do not penetrate the basement membrane. These ulcers can progress to become deeper ulcers once the basement membrane is injured. In the horse, superficial ulcers are commonly seen associated with protein deposits in the anterior stroma
Systems affected—ophthalmic

Signalment

All ages and breeds affected.

Signs

Chronic superficial corneal erosions have an opalescent grayish color, display faint retention of fluorescein dye, and have thin, undulating, acellular, stromal surface membranes
Erosions are surrounded by a loose lip of migrating, nonattached epithelium, corneal vascularization, and crystalline stromal deposits
Minimal uveitis is noted

Causes and Risk Factors

Unknown; possible primary corneal disease with chronic secondary irritation. For example, this may be secondary to acute corneal ulceration from rubbing of a silicone subpalpebral lavage system. Aged horses, or those that are immunocompromised, are more commonly diagnosed with refractory superficial ulcers than other populations.

Diagnosis ⬆ ⬇

Outline

Differential Diagnosis
CBC/Biochemistry/Urinalysis
Other Laboratory Tests
Imaging
Other Diagnostic Procedures
Pathologic Findings

DIAGNOSIS

Differential Diagnosis

Lid abnormalities such as distichiasis, trichiasis, and entropion; neuroparalytic and neurotrophic keratitis; keratoconjunctivitis sicca; corneal dystrophies; and corneal foreign bodies
Inappropriate topical corticosteroid therapy causing delayed corneal healing

CBC/Biochemistry/Urinalysis

N/A

Other Laboratory Tests

Rule out infectious causes (bacterial or fungal) with corneal scrapings for cytology and culture.

Imaging

N/A

Other Diagnostic Procedures

N/A

Pathologic Findings

Histologically, ulceration with a thin membrane of altered corneal stroma, representing corneal stromal sequestration
Lack of epithelial migration and/or attachment onto the ulcerated surface is present

Treatment ⬆ ⬇

TREATMENT

Epithelial debridement of the loose lip of epithelium
Debridement of the ulcer and disruption of the superficial membrane with a diamond burr
Grid keratotomies may be used with caution on eyes that have been confirmed to be free of infection
Superficial keratectomy
Contact lenses act as bandages. A partial temporary tarsorrhaphy may improve retention of the contact lens
Prevent self-trauma with a hard- or soft-cupped hood

Medications ⬆ ⬇

Outline

Drug(s) of Choice
Contraindications/Possible Interactions

MEDICATIONS

Drug(s) of Choice

Topical broad-spectrum antibiotics (e.g. chloramphenicol, neomycin–polymyxin–gramicidin)
Topical serum every 2–4 h or topical polysulfated glycosaminoglycans TID (Adequan; diluted with artificial tears solution to 50 mg/mL) may be beneficial

Contraindications/Possible Interactions

Gentamicin and the fluoroquinolone antibiotics topically may slow corneal healing
If an infection of the corneal defect is not ruled out first by culture and/or cytology, a grid keratotomy can potentially lead to an infection of the deep corneal stroma with loss of vision or globe
Solutions, rather than ointments, are the preferred formulation for refractory superficial ulcers

Follow-up ⬆ ⬇

FOLLOW-UP

Expected Course and Prognosis

Lavage system-induced ulcers are notoriously slow to heal
Infection is a risk owing to epithelial loss
Scarring of the cornea may result

Miscellaneous ⬆ ⬇

Outline

Associated Conditions
See Also

MISCELLANEOUS

Associated Conditions

Infection
Uveitis

See Also

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Basics ⬇

Diagnosis ⬆ ⬇

Treatment ⬆ ⬇

Medications ⬆ ⬇

Follow-up ⬆ ⬇

Miscellaneous ⬆ ⬇

Suggested Reading ⬆ ⬇

Author(s) ⬆