Clinical Management of Corneal Ulcers – Simple vs. Complicated

Overview:

Corneal ulcers are common in veterinary patients, resulting in discomfort and potential loss of vision and/or eyeball if not treated rapidly and appropriately. The presentation will begin with a definition and characterization of corneal ulcers (superficial, stromal, descemetocele, perforation), and discuss causes and consequences of corneal ulcers in veterinary medicine. From a clinical perspective, corneal ulcers can be defined as “simple” (superficial and less than 1 week in duration) or “complicated” (deep and/or longer than 1 week in duration). Simple corneal ulcers should be managed with prophylactic antibiotherapy, plus or minus other medications, such as topical atropine and an oral nonsteroidal anti-inflammatory drug (NSAID), and should be rechecked within 7 days. For complicated corneal ulcers, the appropriate management depends on the underlying cause:

1. The etiology has not been identified / removed. A thorough eye examination should be performed on every patient with a corneal ulcer, including Schirmer tear testing and evaluation of the eyelids; this will help rule out dry eye, eyelid conformational abnormalities (e.g, entropion, eyelid mass), eyelash abnormalities (e.g, distichiasis, ectopic cilia), foreign body, or other causes of corneal ulceration.

2. Corneal infection. In cases of infection, corneal cytology plus culture/sensitivity testing can help the clinician select the most appropriate therapy. Empirical therapy can be initiated with 2 topical antibiotics (covering gram-positive and gram-negative bacteria), topical serum (collagenolysis), and other medications, with a recheck visit in 2 to 3 days. Surgical options can also help manage deep/infected corneal ulcers.

3. Superficial non-healing ulcer (“indolent” or “Boxer” ulcer). For this type of ulcer, known as a “spontaneous chronic corneal epithelial defect” (SCCED), there is abnormal adherence between the corneal epithelium and stroma due to abnormal tissue in the anterior stroma (acellular, hyalinized zone). To improve healing, this abnormal tissue should be debrided. Options include corneal debridement with cotton swabs, diamond burr debridement, grid keratotomy, and superficial keratectomy.

Learning Objectives:

• Recognize the different types of corneal ulceration in domestic animals
• Understand the potential causes for corneal ulceration in domestic animals
• Understand common pitfalls of corneal ulcer management in private practice
• Learn how to appropriately manage a superficial non-infected corneal ulcer (simple ulcer)
• Recognize the main reasons for inappropriate healing of corneal ulceration in domestic animals (complicated ulcer)
• Learn how to appropriately manage a ‘complicated ulcer’ in domestic animals