Impact of prolonged surgical mask versus KN95 respirator use on tear film stability in healthcare workers.

OBJECTIVES

This study aimed to evaluate and compare the effects of prolonged daily wear of a surgical mask (SM) versus a KN95 respirator on tear film stability in healthcare workers.

METHODS

Forty-eight healthcare workers (96 eyes) were randomly assigned to wear either an SM or a KN95 respirator. Corneal fluorescein staining (FS), tear film break-up time (BUT), Schirmer I test (SIt), and the ocular surface disease index (OSDI) questionnaire were assessed at baseline without a mask (T0), after 8 h of continuous wear (T1), and after 1 week of daily wear (≥ 8 h/day, T2).

RESULTS

In the SM group, the FS score at T2 was significantly higher than at T0 and T1 (both p < 0.05). In the KN95 group, the FS score at T2 was significantly higher than at T0 (p < 0.05). BUT decreased significantly and progressively from T0 to T2 in both groups (all p < 0.0167). No significant changes in SIt or OSDI scores were observed over time within either group. Furthermore, no significant differences in FS, BUT, SIt, or OSDI scores were found between the two mask groups at any time point.

CONCLUSIONS

Prolonged daily use of both SM and KN95 respirators over 1 week negatively affected tear film stability in healthcare workers, as indicated by a significant reduction in BUT and altered FS scores. The similar magnitude of effect for both mask types suggests that the impact is related to mask wear in general rather than to a specific design. These preliminary findings warrant confirmation in larger, controlled studies with longer follow-up periods.