The Effect of Face Masks during COVID-19 Pandemic on Ocular Surface Temperature-A Clinical Thermographic Analysis

The Effect of Face Mask Wear on the Ocular Surface and Contact Lens Microbiome

OBJECTIVES

As face mask wear can result in the redirection of nasal and oral exhalation toward the ocular region, this study investigated the impact of face mask wear on the conjunctiva, eyelid margin, and contact lens (CL) surface microbiome.

METHODS

In this prospective, cross-over study, experienced CL wearers (N=20) were randomized to wear a face mask for 6 hr/day (minimum) for a week or no mask for a week. The conjunctiva, eyelid, and CLs were then sampled. After a 1-week washout period, participants were crossed over into the alternate treatment for 1 week and sampling was repeated. Sampling was bilateral and randomly assigned to be processed for culturing or 16S ribosomal(r) RNA gene sequencing.

RESULTS

Culturing showed no effect of mask wear on the average number of bacterial colonies isolated on the conjunctiva, eyelid, or CL, but there was increased isolation of Staphylococcus capitis on CL samples with mask wear ( P =0.040). Culture-independent sequencing found differences in the taxonomic complexity and bacterial composition between the three sites ( P <0.001), but there was no effect of bacterial diversity within and between sites. Mask wear did not impact dry eye or CL discomfort, but increased ocular surface staining was reported ( P =0.035).

CONCLUSIONS

Mask wear did not substantially alter the microbiome of the conjunctiva, eyelid margin, or CL surfaces in uncompromised healthy eyes.

COVID-19 pandemic and impact of universal face mask wear on ocular surface health and risk of infection

Universal mask wear is an effective public health intervention to reduce SARS-Cov-2 transmission, especially in enclosed public spaces and healthcare environments. Concerns have been raised about possible transmission of the SARS-Cov-2 through ocular secretions, leading to enhanced protective measures during ophthalmic procedures. However, there is some evidence for air jets from the upper edge of the surgical mask to the ocular surface, especially when the mask is not well fit. Prolonged airflow towards the ocular surface during expiration may alter tear-film stability, leading to hyperosmolarity and ocular surface inflammation. This also raises the question of whether the ocular surface is contaminated with oral flora from airflow directed toward the eyes, thus increasing the risk of ocular infection. Herein we review the impact of patient face mask wear on the ocular surface, eyelids and risk of ocular infection, particularly during ocular surgery. There is some evidence for increased incidence of dry eye or eyelid disease during periods of mandatory face mask wear. While high daily exposure is consistent with a direct association, this should be mitigated by various cofounding factors which could also affect the ocular health during the COVID-19 pandemic. An increased risk of post-intravitreal injection endophthalmitis, possibly due to face mask wear by the patient, including culture-positive endophthalmitis, has been reported in one retrospective study. Several measures have been shown to prevent or limit the risk of developing dry eye disease or exacerbation, eyelid cyst, and ocular infection during intravitreal injections.

Real or MADE-up: Investigating Mask-Associated Dry Eye (MADE) as an emerging syndrome

Mask-Associated Dry Eye (MADE) has emerged as a consequence of widespread face mask usage during the Covid-19 pandemic. This review critically assesses the available evidence. A comprehensive search on PUBMED and EMBASE was conducted to identify studies on MADE, which were then categorized based on their design. A total of 26 studies were critically appraised, with the majority exhibiting poor study design quality. Investigating the impact of mask use on ocular surface irritation faced challenges due to global mask mandates, pandemic-related behavioural changes, and a lack of validated methods to measure the response to mask wear. Among the 15 studies, 12 reported a statistically significant reduction in TBUT associated with mask wear; however, the median decrease of 1.3 s was considered clinically insignificant. Results from Schirmer's test in 8 studies varied, with 5 studies reporting a decrease, contradicting the hypothesis of misdirected airflow. Out of 7 studies on corneal and conjunctival staining, 6 indicated a worsening associated with mask wear. Five studies investigating OSDI scores reported an increase following mask wear, but 3 studies repeated the survey too soon. Limited evidence suggests that masks may cause mild ocular surface irritation, but the quality and certainty of this evidence remain low. Methodological limitations were prevalent across the majority of studies, and the observed changes were minimal. Therefore, it is unlikely that significant ocular surface pathology will develop in the majority of mask wearers. Currently, there is insufficient data to support the establishment of a new syndrome.

Investigating the Impact of COVID-19 Infection on Dry Eye Parameters

PURPOSE

This study aims to compare dry eye parameters before and after COVID-19 infection in dry eye patients.

METHODS

We included 44 dry eye patients (88 eyes) from our existing dry eye cohort, with 22 belonging to the post-COVID-19 group due to a prior COVID-19 infection and the other 22 forming the non-COVID-19 group as they had no history of COVID-19. We examined and compared the dry eye parameters of the post-COVID-19 group, including the ocular surface disease index (OSDI), Schirmer's test results (ST), non-invasive Keratography tear break-up time (NIKBUT), lipid layer thickness (LLT), Meibomian gland dysfunction (MGD), and the grading of papillae and follicles, both before and after the COVID-19 infection. We also compared the dry eye parameters difference of the post-COVID-19 group with the non-COVID-19 group.

RESULTS

The post-COVID-19 group was comprised of individuals with an average age of 38.36 ± 14.99 years, of which 82% were female. The time interval between the two tests was 16.92 ± 5.40 months, which did not differ significantly from the non-COVID-19 group. Compared to the pre-COVID-19 eyes, the post-COVID-19 eyes showed a significant decrease in the average LLT (52.86 ± 18.00 nm vs. 63.00 ± 22.40 nm, p < 0.001), as well as the maximum LLT (67.89 ± 20.81 nm vs. 78.48 ± 20.55 nm, p < 0.001). The MGD in both the upper (1.75 ± 0.84) and lower eyelids (1.43 ± 0.73) worsened after a COVID-19 infection. Additionally, the grading of papillae was worse following a COVID-19 infection (0.61 ± 0.69 vs. 0.16 ± 0.37, p < 0.001). The multivariate linear regression model revealed a negative association between COVID-19 infection and NIKBUT-average (β = -2.98, 95%CI: (-5.82, -0.15), p = 0.039), LLT-average (β = -14.12, 95%CI: (-22.66, -5.59), p = 0.001), and LLT max (β = -15.65, 95%CI: (-23.09, -8.20), p < 0.001).

CONCLUSION

From preliminary results, we concluded that dry eye patients who have been infected with COVID-19 appear to have a more severe dry eye condition, as evidenced by lower LLT, worse papillae and MGD, and shorter NIKBUT. It is important to raise awareness of this potential long-term symptom of COVID-19, especially among existing dry eye patients.

Microbiological Profile of Infectious Keratitis During Covid-19 Pandemic

Purpose

The Covid-19 pandemic introduced significant changes in our daily life, including the widespread use of face masks. The purpose of this study was to assess if significant changes occurred in the microbiological profile of infectious keratitis.

Patients and Methods

A retrospective study was performed, based on a survey review of the electronic medical records of all patients with presumed infectious keratitis, between March 2020 and October 2021. The microbiological isolates in this sample (pandemic group) were compared with those obtained in our center between 2009 and 2018 (pre-pandemic group).

Results

A total of 194 samples were included in the pandemic group. We obtained a culture-positivity rate of 43.3%, which was significantly higher when compared with the pre-pandemic data (35.15%, p = 0.033). Several further significant differences were found between the pandemic and the pre-pandemic groups: the proportion of bacteria, including gram-positive and gram-negative groups, was higher in our sample (pre-pandemic vs pandemic: 76.78% vs 83.33%, p = 0.010; 53.35% vs 60.71%, p = 0.016; 23.43% vs 34.52%, p = 0.005, respectively); two populations of Gram-positive bacteria found in this study were not isolated in the pre-pandemic sample - Dolosigranulum pigrum and Propionibacterium spp.; and two bacterial isolates were significantly increased in our sample - Corynebacterium spp. (18.41% vs 29.76%, p = 0.003) and Pseudomonas aeruginosa (9.00% vs 16.66%, p = 0.012).

Conclusion

In conclusion, significant changes were found in the microbiological profile of infectious keratitis in our center during the Covid-19 pandemic. While these changes could be related to face mask use, more observational and experimental studies are needed to explore this possible association.

Face mask use and effects on the ocular surface health: A comprehensive review

In the COVID-19 period, face masks increased exponentially. Several studies suggest that the rise in ocular discomfort symptoms during the pandemic is mostly part of dry eye disease and that these are due to the effect of face masks, resulting in the newly described term MADE, for "mask-associated dry eye". The most commonly proposed mechanism states that wearing a face mask creates an unnatural upward airflow towards the ocular surface during expiration, although the increased temperature, humidity and levels of carbon dioxide of the exhaled air, stress, increased use of video display terminals, as well as changes in the ocular microbiota may contribute. Evidence supports that the use of face masks causes an increase in dry eye disease symptoms, a decreased tear break-up time, corneal epithelial trauma, periocular temperature changes and inflammatory markers secretion. Given that the use of masks may be frequent in some settings in the near future, it is important to establish its effects and consequences on the ocular surface.