Medication can be primary cause for optic neuropathy
DANA POINT, Calif. — When a patient presents with bilateral centrocecal scotomas, the culprit may be on the patient’s list of medications, suggested Leonard A. Levin, MD, PhD, speaking here at the Ocular Drug & Surgical Therapy Update meeting.
In patients with centrocecal scotoma, differential diagnosis may include Leber’s hereditary optic neuropathy, nutritional amblyopia, tobacco or alcohol amblyopia and toxic optic neuropathy, Dr. Levin said.
“The first thing I want you to remember is, whenever you see this picture of bilateral centrocecal scotomas … that is a very specific way to a diagnosis,” he said.
Dr. Levin recommended reviewing the patient’s list of medications before ordering blood tests, MRIs or other scans, which can sometimes take a week or more to process.
“Take one minute to go over the medication list,” Dr. Levin told attendees. In one case he discussed in his presentation, linezolid was the toxicity culprit.
“Linezolid is a drug that has only recently come onto the market. It is the equivalent of vancomycin in a pill,” he said. “It is only approved by the Food and Drug Administration for 30 days, but people are using it for longer. When they do, they get an optic neuropathy.”
Other agents that may be at the root of toxic optic neuropathy include methanol, ethambutol, Taxol (paclitaxel, Bristol-Myers Squibb) and amiodarone, Dr. Levin said.