Knowledge is good

Jun 14, 2018

As a first year resident, everything was new and I was full of questions. My chief resident, Reay, is famous now but back then he was just a regular guy-but a regular guy with all the answers. One day, in my first week of residency, I saw my first corneal ulcer and went to talk to Reay.

“I have a patient with what I think is a bacterial ulcer. How do I scrape it for culture without poking a hole through the cornea?” I asked. Reay said he would show me and came back with me.

Expert Opinion

Reay examined the cornea with the slit lamp and scraped the ulcer with a spatula while I watched through the side scope. He told me to press firmly to get a good sample, and we plated the specimen directly on the culture plates. I thanked him for showing me.

“The culture will grow a gram positive bug,” he said, and walked away. I was skeptical. Reay may know a lot, I thought, but no one can see bacteria with a slit lamp.

The next morning we residents rounded at 6:30 and then attended our lecture on “The Red Eye.” Allan, our lecturer, was already pretty famous and would later become president of the American Academy of Ophthalmology, but to residents like me he seemed to be just a friendly and helpful teacher. Having seen my patient with the ulcer the day before, and knowing I would be seeing many patients with red eyes during my years as a resident, I paid close attention. Allan shared a few pearls, including: “A unilateral red eye in a hospitalized patient is herpes simplex until proven otherwise.” That sounded like a useful piece of knowledge and I wrote it down.

Later that day, I was in clinic near Reay when the nurse came up to me. “One of the medicine floors is sending a consult for you. An inpatient with one red eye.” I looked at her and said, “It’s herpes simplex, most likely.”

Reay looked at me for a few seconds. He seemed skeptical. “Call me when the patient gets here,” he told the nurse. While waiting for the inpatient consult to arrive in her wheelchair, I checked the microbiology report on the corneal ulcer from the day before. The culture was growing Staphylococcus aureus.

Putting pearls to use

My inpatient arrived and a slit lamp examination showed a large herpes simplex dendrite, just like the photos I had seen in textbooks and in my lecture that morning. I explained to the patient what the problem was and that she would get better with a topical antiviral. My chief walked in, sat down at the slit lamp, and took a look for himself. I then sent the patient back to her room. I turned to Reay.

“The culture from my ulcer patient yesterday grew Staph aureus. How did you know it would be gram positive?” Reay answered: “Easy. Gram negative bacteria like Pseudomonas produce lytic enzymes that digest the corneal stroma. When I scraped that ulcer, the stroma was firm.” Then it was Reay’s turn. “How did you know this woman would turn out to have herpes keratitis?” he asked.

“Easy,” I replied. “A unilateral red eye in a hospitalized patient is herpes simplex until proven otherwise. Everybody knows that.” “Knowledge is good” is the motto of Faber College in the movie “Animal House.” Being a resident, and learning new things every day, proved the truth of this statement. It is the fortunate ophthalmologist who is able to continue learning at least one new thing every day throughout his or her career.  


Peter J. McDonnell, MD
Director of the Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, and chief medical editor of
Ophthalmology Times. He can be reached at 727 Maumenee Building 600 N. Wolfe St. Baltimore, MD 21287-9278

Phone: 443/287-1511 Fax: 443/287-1514