All of us have been there in residency: You get the phone call Friday afternoon for referral in of a “great teaching case” — i.e., a corneal ulcer. Come to find out, it’s not just limited to residency training.
All kidding aside, corneal ulcers are one of the most common diseases referred to ophthalmology practices and can present some significant diagnostic challenges. The very first patient I examined in private practice had a contact lens-related central corneal ulcer that already had been treated for three weeks without improvement and with progressive thinning. I had to use almost all the “tricks” I learned in residency and fellowship to successfully treat this ulcer.
What were they? The top seven clinical pearls that I have learned in diagnosing and managing difficult corneal ulcers (with special thanks to my mentors on this subject, Mark Mannis, MD; Ivan Schwab, MD; and Elmer Tu, MD) are:
- Take a careful, detailed history. Information on contact lens use, immunodeficiency status and previous infections may all provide diagnostic clues to the causative infectious agent. Does the patient have a history of cold sores? Shingles? Diabetes? These factors could not only help identify the pathogen, but also may provide an explanation for a non-healing corneal ulcer.
- Test corneal sensation. Before you place any drops in the eye, be sure to check corneal sensation. Oftentimes, decreased corneal sensation may indicate an underlying neurotrophic ulcer or herpetic ulcer.
- Check intraocular pressure. Intraocular pressure may still be elevated even in the presence of a corneal ulcer, and may impede healing if left untreated. If there is a central corneal ulcer, checking tonometry by applanation may be difficult (not to mention less accurate in the presence of corneal edema). Therefore, consider using a tonopen or tonometer, if available.
- Examine the ocular adnexae. When a large corneal ulcer is staring you in the face, it is sometimes easy to overlook the remainder of the anterior segment exam. However, careful examination of the ocular adnexae (of both eyes) may reveal subtle clues that will lead you to the primary diagnosis. Look carefully at the fornix and evert the upper lid. Are there bulbar follicles that may be suggestive of herpetic disease? Or perhaps a foreign body underneath the lid?
- Culture central corneal ulcers. Most peripheral ulcers may be treated empirically with broad-spectrum antibiotics; however, central corneal ulcers should be cultured prior to initiation of therapy whenever possible. Even if you don’t have access to all the different types of culture media you had in residency, a gram stain with culture on blood and chocolate agar will provide you most of the information you need. If you don’t have access to culture plates at your practice, consider contacting the microbiology lab at the local hospital, as they may be able to assist you.
- Treat other exacerbating factors. The health of the ocular surface can go a long way in making — or breaking — your treatment plan. For example, conditions such as blepharitis or tear-film deficiency may greatly impair the healing of a corneal ulcer. A thorough assessment of the ocular surface and the use of doxycycline, artificial tears and punctal plugs when indicated are key components of managing difficult-to-heal corneal ulcers.
- Know when to refer. Most corneal ulcers can be adequately treated by a comprehensive ophthalmologist in a private practice setting. However, if there is significant progression of a corneal ulcer while on treatment, especially with advanced thinning, consider referring to a corneal specialist. A timely referral to a specialist may save a patient from an emergency keratoplasty procedure under less-than-ideal conditions.
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About the Author: Lisa M. Nijm, MD, JD, practices as a full-time corneal, external disease and refractive specialist at North Bay Eye Associates in Sonoma County, Calif. She completed her residency at the University of Illinois Eye and Ear Infirmary, Chicago, in 2008, followed by a corneal fellowship at the University of California at Davis, Sacramento, in 2009. Dr. Nijm also serves as a member of the YO Info editorial board.