Increased risk of endophthalmitis may be associated with face masks worn by patients during intravitreal injection procedures, according to a study recently published in Retina.

Conducted by Amir Hadayer et al. of the Sackler Faculty of Medicine of Tel Aviv, Israel and the Department of Ophthalmology of the Rabin Medical Center of Petah Tikva, this prospective qualitative interventional study aimed at investigating the safety of protective face masks worn by patients during intravitreal injections.

Ten healthy volunteers were asked to wear different surgical face masks, and detection of air leaks towards the eyes was monitored by the investigators using professional thermal cameras.
The experiment was repeated three times for each of the three types of face masks: a regular surgical face mask with elastic ear loops, a regular surgical face mask with four tying strings and a 2200N95 particulate face mask. The periocular area was examined during normal respiration, speech and deep respiration activities. A FLIR A310 thermal camera and an EyeCGas 2.0 optical gas imaging camera were used to identify air leaking from the masks’ upper side and tunneled towards the injection site. The EyeCGas 2.0 camera is a professional super-sensitive thermal camera used in industry to detect minute fugitive gas leaks from high-pressure gas lines.
Air jets directed towards the eyes from the upper side of face masks were detected in 81% of the cases. 



According to the authors, those leaks of exhaled breath could contaminate the injection site during intravitreal injections, thus increasing the risk of endophthalmitis.
Current recommendations suggest that healthcare staff and patients should wear face masks as a protective measure against the ongoing COVID-19 pandemic. However, “when patients wear surgical face masks during intravitreal injections, the risk of surgical field contamination is paradoxically increased,” they wrote.

The authors recommended that face masks during intravitreal injections should be used with caution, and additional safety measures should be taken to ensure a safe operative field, avoiding contamination of both the eye surface and the needle by salivary flora. They suggested that adhesive draping around the injected eye could block or reduce the passage of contaminated air from the mouth and nose through the mask’s upper edge. Alternatively, a medical adhesive tape could be fixed across the upper border of the face masks. 

“We performed our study prior to the COVID-19 pandemic. We wanted to investigate whether face masks used by the patients might increase safety since we are not sure whether the bacteria that cause endophthalmitis comes from the doctor or from the patient. However, initially, we needed to make sure that there was no harmful effect involved,” Amir Hadayer, MD, said. 


As the COVID-19 outbreak became a global health crisis in February 2020, the use of protective equipment such as face masks has become standard practice in clinical procedures ranging from regular visits to small surgical procedures such as intravitreal injections. 

“Since we entered the epidemic with this prior knowledge, we have not injected patients wearing face masks, and we have not encountered problems. Hopefully, this information will reach doctors before any further cases or outbreaks of endophthalmitis occur,” Hadayer concluded.


Source: Hadayer A, Zahavi A, Livny E, Gal-Or O, Gershoni A, Mimouni K, Ehrlich R. PATIENTS WEARING FACE MASKS DURING INTRAVITREAL INJECTIONS MAY BE AT A HIGHER RISK OF ENDOPHTHALMITIS. Retina. 2020 Sep;40(9):1651-1656. doi: 10.1097/IAE.0000000000002919. PMID: 32701593.