Vol. 47 No. 2 Original Research PDF

The Effect of Wearing N95 Respirator Masks on Intraocular Pressure of Health Care Workers

Denise Patricia M. Granada, MD
Paolo S. Silva, MD
Rainier Victor A. Covar, MD, MMed

The Medical City – Eye and Vision Institute, Pasig City, Philippines

Corresponding Author: Denise Patricia M. Granada, MD
Clinic Address: Eye and Vision Institute, 4th Floor Podium Building, The Medical City, Ortigas Ave., Pasig City, Philippines 1604
Contact Number: (02) 8635-6789 local 7877
Email Address: denisegranada@gmail.com

Disclosure: The authors do not have any financial disclosures or conflicts of interest. The study received financial support from The Medical City Clinical and Translational Research Institute.


Objective: We determined if there was a significant change in the intraocular pressure (IOP) of healthcare workers with extended use of N95 masks.

Methods: This was a prospective time-series study involving 58 eyes of 29 healthcare workers who were assigned to 3 groups: surgical mask (control) and 2 intervention arms consisting of valved N95 (8511, 3M, USA) and non-valved N95 (8210, 3M, USA) masks. Each participant underwent IOP measurements of both eyes by Goldmann applanation tonometry at baseline, 5 minutes, 1 and 4 hours of mask use on three separate days. The primary outcome was the difference in IOP between the N95 and surgical mask groups.

Results: Mean baseline IOP of the cohort was 13.85 ± 1.11 mmHg with no significant difference among the groups. Compared to surgical mask use, mean IOP was increased at the 1 hour and 4 hour time points with valved N95 use (+0.88, p<0.001; +1.48, p<0.001 respectively) and increased at the 5 minute, 1 hour and 4 hour time points with nonvalved N95 use (+0.52, p=0.01; +1.07 p<0.001; +1.62, p<0.001, respectively).

Conclusion: There was a statistically significant increase in IOPs with prolonged N95 mask use. However, the levels of IOP increase were less than 2 mmHg and may be not clinically significant.

Keywords: Goldmann applanation, intraocular pressure, N95 mask, glaucoma, surgical mask, breathing resistance