Face masks can cause bacterial spread to the eyes during intravitreal injections



SAN ANTONIO – The face masks were seeded “almost instantly” with oral and nasopharyngeal bacteria, posing a potential risk of spread to the eyes during intravitreal injections for macular degeneration, according to a study reported here.

The masks of the 73 patients involved in the study tested positive for a variety of common organisms, as well as some rare microbes. Bacteria grew on both sides of the masks, regardless of the age of the mask material.

Despite the proximity of infectious organisms, no patient developed endophthalmitis, Avinash V. Honasoge, MD, PhD, of the Retina Institute of St. Louis, reported at the meeting of the American Society of Retina Specialists ( ASRS).

“We did not find any correlation between mask age and indoor or outdoor growth, which suggests [other evidence] that even a few hours after wearing a mask, you can see bacteria on them, ”he said. “Men had greater growth inside the mask than women. This has already been assumed to be due to facial hair. “

“Everyone here does intravitreal injections, and you will have to make a choice,” Honasoge added. “How are you going to try to protect the periocular surface after sterilizing it with iodine?” Are you going to tape the mask, institute a no-talk policy? Maybe just remove the mask and dilute the particles and away from the periocular space? The other question is, as this pandemic continues, will we see a change in the flora present for our post-injection endophthalmitis?

The COVID-19 pandemic has led to widespread use of face masks, made of a variety of materials and of varying quality. Ill-fitting masks present a clear risk to patients during intravitreal injections. Changing masks is not a solution, he continued. A few hours after putting on a fresh mask, bacterial RNA can be isolated and bacteria can adhere to a mask for hours after wearing.

“While masks are very effective at blocking forward transmission, if you don’t stick a mask on or have an ill-fitting mask, you can get an upward flow of particles,” Honasoge said. “Not speaking seems to help. Recording seems to help, but the question we were asking ourselves is what type of bacteria are we dealing with.

To examine the problems of bacterial variety and quantity, the researchers prospectively evaluated 73 patients with appointments for intravitreal injections. Patients wearing N95 / KN95 masks were excluded, as were patients receiving intravitreal injections of endophthalmitis antibiotics.

Patient masks were swabbed internally and externally and evaluated for Gram stain, aerobic culture, and speciation. The main outcomes were bacterial composition and mask growth.

The study population had a median age of 76 to 77 years and the mask material was cloth in 31 cases; surgery in 42. The age of the mask ranged from less than a day to over a month. More than a third of the masks had been worn for a week or more. One patient had not washed his fabric mask for over a year.

Laboratory analysis showed bacterial growth inside 97.2% of the masks and 90.2% on the outside. Some masks had bacteria inside and out and some had more than one type of bacteria.

“The bacteria included the usual suspects, such as coagulase-negative staphylococcus and streptococcus viridans, but also certain types of bad players – enterobacter, E. coli, bacillus. Each mask had between one and two species on either side of the mask. “

Quantification studies have suggested strong growth both inside and outside the masks, he added.

A second study reported at the same ASRS “Symposium on Inflammatory and Infectious Diseases” provided further evidence of upward scattering of microbes by patients wearing masks during sham intravitreal injections. The study involved 15 healthy volunteers who wore different types of masks, with and without tape, and with and without a silent environment (the latter consisting of a standardized script).

In total, patients participated in the assessment of six mask scenarios, said Samir Patel, MD, of Mid-Atlantic Retina, Wills Eye Hospital and Thomas Jefferson University, both in Philadelphia. Culture plates were attached to the forehead of each participant, and the plates were grown for both aerobic and anaerobic species. A total of 90 cultures were obtained during each of the no-talk and talk settings.

The results showed that a properly fitted mask with tape on top and an N95 mask performed best, and both were associated with an average of 0.20 colony forming units (CFU) during adjustment let alone. The N95 performed better numerically in the talk simulation, but did not differ significantly from the mask fitted with tape (0.20 vs. 0.27 CFU). A well-fitting mask without tape gave significantly poorer results (1.13 CFU without speaking, 1.40 CFU with speaking, P

The organisms most often isolated in talking and silent simulations were Staphylococcal spp (51-64%).

“There was no difference in bacterial dispersion between tight-fitting surgical masks with duct tape and N95 face masks,” Patel said. “Gluing the top portion of the patient’s face mask may limit bacterial dispersion when performing intravitreal injections. However, the clinical implications of these findings are unknown, and it is not clear whether the alterations in the number. units forming colonies around the eye necessarily alter the clinical risk of endophthalmitis. “

  • Charles Bankhead is editor-in-chief for oncology and also covers urology, dermatology and ophthalmology. He joined MedPage Today in 2007. To follow


Honasoge has not disclosed any relationship with the industry. Some co-authors have revealed relationships with Allergan, Bausch and Lomb, Regeneron, Genentech, and Dutch Ophthalmics.

Patel did not disclose any relationship with the industry. Some co-authors have disclosed relationships with Aerpio, Apellis Pharmaceuticals, Bausch + Lomb, Deciphera, MDIntelleSys, Retina Implant / Wills Eye Hospital, Santen, Topivert, Genentech, Ophthotech, Alcon, Astellas, Iconic, Notal Vision, Novartis, AGTC, AsclepiX, Beaver Endo Optics, BioTime, Covalent Medical, Janssen, Kang Hong Chengdu, Notal, ONL, Optovue, Orbit Biomedical, PanOptica, ProQR, RegenxBio, Sanofi, Second Sight and Alimera Sciences.


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