Eye exams require close physical contact between patients and physicians, which is not an issue, until a pandemic strikes. Last spring, ophthalmologists began improvising with various forms and sizes of plastic sheeting attached to exam equipment to help protect both the patient and them from the virus. Although the innovation made intuitive sense, they had no hard evidence that it did. Until now. New research released at AAO 2020 Virtual, the 124th annual meeting of the American Academy of Ophthalmology, confirms breath shields offer effective protection, allowing ophthalmologists to safely examine patients during a pandemic. And, size matters, larger shields offer better protection.
Because COVID-19 usually spreads from the mouth or nose, the researchers used spray dye to visualize droplets spread when someone coughs or exhales with and without a shield. Researchers tested three options: a large breath shield (45×44 centimeters), a standard small shield (11×11 centimeters), and no breath shield.
Large shields offered the best protection, stopping droplets from spreading when coughing or breathing. Small shields did not provide adequate protection against droplet spread from a cough.
“In response to the pandemic, there was an urgent need to assess the effectiveness of different sized breath shields,” lead researcher Mong-Loon Kuet, MBBChir, FRCOphth, said in an AAO news release. “We hope that the findings will further encourage the universal use of larger breath shields as an important part of a health care provider’s infection control measures.”
The team of researchers conducted a related study in May 2020 using a particle counter, which detects aerosols that are not visible to the naked eye. Both studies suggest larger breath shields are most effective at reducing infectious particle spread.