[Une flambée d'infections oculaires en pleine pandémie de COVID-19 : une réalité ou une coïncidence ?]

Dear Editor,

World Health Organization announced Covid-19 pandemic on March 11, 2020. The virus was detected firstly in Wuhan, china with an unexpected outbreak in all countries around the world [1]. Iran country experienced an extreme outbreak of Covid-19 with over 574,000 case yet and more than 33,000 deaths due to coronavirus disease [2]. As current treatments are limited to supportive and palliative approaches, personal hygiene and keeping hand washes, social distancing and using face mask are the most recommended strategies for disease prevention [3].

During Covid-19 pandemic, many ophthalmologist cancelled unnecessary visits as well as elective surgeries especially those who were working in private clinics. In our practice in Khalili hospital affiliated to Shiraz University of Medical Sciences, we limited ocular surgeries to emergency cases during first peak of Covid-19 pandemic. During the second peak of Covid-19 pandemic, we performed emergency as well as elective surgeries. Surprisingly, we witnessed unexpected increased rate of ocular infection including infectious keratitis and endophthalimitis in post-up visits. We diagnosed two cases of infectious keratitis following corneal collagen cross-linking and three patients with postoperative endophthalmitis in only two weeks’ time. All of patients were wearing face mask postoperatively. Microbiological cultures detected Bacillus bacteria and staphylococcus aureus, normal flora bacteria of mouth cavity. This outbreak of ocular infection enforced us to cancel elective surgeries and to limit our surgeries to only emergency cases for one-week time. The operations have been performed in different rooms with different staff. During recent months, no changes in operation room setting including used materials as well as operation devices have been applied. Herein we would like to discuss a possible factor that might be involved in the recent outbreak of ocular infection.

As all of the patients have used regular facemask with elastic ear loops during operation and/or in the post-operative period to avoid Covid-19 transmission, we postulated that such increased incidence of ocular infection might be associated with using facemask. As we know, it has been recommended that ophthalmologists and patients should avoid talking during intra-ocular injections to lessen the rate of postoperative endophthalmitis [4]. Recently, in an interesting study by Hadayer et al., it was demonstrated that air could leak from upper border of face mask toward eyes in more than 90 percent of individuals even after fitting the face mask. They supposed that using face mask by patients during intraviteral injection could leads to a higher risk of endophthalmitis as air leak could transmit bacterial flora of mouth toward eyes [5]. In addition, higher rate of dry eye symptoms has been reported in those wearing face mask due to increased tear evaporation as a consequence of air flow toward eyes [6]. In our study, we observed patients with infectious keratitis and endophthalmitis after corneal collagen cross-linking surgery, vitrectomy or phacoemulsification procedures. We hypothesize that using facemask not only in intraviteral injections, but also in other ophthalmic surgeries such as corneal surgeries might result in higher risk of ocular infections. This outbreak of ocular infection in our practice could be due to transmission of normal bacteria flora of mouth toward eyes by using facemask during Covid-19 pandemic. However, possibility of coincidence should be considered.

To conclude, we postulate that patients wearing facemask during ophthalmic procedures or in the post-operative days might be at higher risk of ocular infection. We emphasize the importance of appropriate antibiotic therapy during the first postoperative weeks especially in corneal procedures until complete re-epithelialization of cornea occurs.

Disclosure of interest

The authors declare that they have no competing interest.