In a study reported in the Archives of Ophthalmology, Dr. Colin McCannel and colleagues at the Jules Stein Eye Institute in Los Angeles simulated multiple eye injection procedures in an ophthalmologist’s office during which volunteers stood in front of an exam chair, which had a plate for culturing bacteria placed where a patient’s head would be.

The volunteers read from a script for five minutes under different conditions — facing directly at the imaginary patient, with or without a mask, or facing sideways mask-free. Then, they stood in silence for five minutes. The volunteers also lay down on the exam chair and read the script with a bacteria plate mounted to their own foreheads.

When the 15 volunteers talked while wearing a mask or stood in silence, hardly any bacteria grew on the plates. But when they didn’t wear a face mask, either while facing the patient or turned away, most plates sprouted bacteria colonies. And when “patients” talked themselves, about half of the plates grew bacteria.

The researchers concluded that wearing a face mask or remaining silent during an eye injection procedure significantly decreasesthe risk of infection. Accordingly, physicians performing intravitreous injections should consider eitherwearing a face mask or minimizing speech, and should encourage patients to minimize speech during the procedure.

Read the abstract ^[1]. 

Read the full story ^[2].