CHOROIDAL CHANGES DUE TO LONG-TERM USE OF N95 FACE MASKS.

PURPOSE: We aimed to examine the changes in choroidal stroma and vascular system due to long-term use of N95 mask in healthcare workers. METHOD: The healthcare workers included in the study were between the ages of 18-50, with best corrected visual acuity (BCVA) 10/10, spherical and cylindrical refractive errors less than 3 diopters, intraocular pressures (IOP) within normal limits, and axial lengths (AL) less than 25 mm. The choroid was imaged with enhanced depth imaging (EDI) techniques using SD-OCT. The choroidal vascularity index (CVI), total choroidal area (TA), luminal area (LA), and stromal area (SA) were measured in the subfoveal 2 mm area. Measurements were first made after wearing the N95 mask for at least 2 hours without removing it and repeated 1hour after removing, while doing office working. RESULTS: The study included 62 eyes from 62 participants (32 women [%51.61]; 30 men [%48.39]). The mean age of patients was 33.81± 8.88 years (20-50 years). The differences in subfoveal TA, LA, SA between 2 hours of N95 mask use and 1 hour after removal of the mask were statistically significant (p<0.05 for each). However, the difference in CVI between the mask use and removal of the mask was not statically significant (p=0.537) CONCLUSION: Due to CO2 retention and hemodynamic changes, choroidal vascular flow, the choroidal vascular area, and the choroidal stromal area may be affected by prolonged use of masks.

Evaluation of the effect of n95 face mask used by healthcare professionals on choroidal thickness.

PURPOSE: We aimed to show the changes in choroidal thickness (CT) with spectral domain optical coherence tomography (SD-OCT) after prolonged use of N95 mask. METHOD: The healthcare workers who use the N95 face-mask, between 30-50 years of age who have best corrected visual acuity (BCVA) ≥10/10, spherical or cylindrical refraction errors less than 2 diopters, with normal intra ocular pressure (IOP), axial length (AL) between 22-24 mm included in the study. The choroid was imaged with enhanced depth imaging (EDI) techniques using SD-OCT. CT was measured, subfoveal, at 1000 µm nasal and temporal of the center of the fovea. Measurements were first made after wearing the N95 mask for at least 2 h without removing it and repeated 15 min after removing. RESULTS: After 2 h of the N95 mask using without removal, the mean subfoveal CT was 293.56 ± 76.12(min:185, max:479), the mean temporal CT was 253.81 ± 63.48(min:172, max:384), the mean nasal CT was 239.18 ± 53.92(min:139, max:356). Fifteen minutes after removal of the N95 mask, the mean subfoveal CT was 250.56 ± 52.48(min:172, max:397), the mean temporal was 218.40 ± 53.58(min:129, max:354), the mean nasal CT was 210.67 ± 53.31(min:132, max:366). The differences in subfoveal, temporal and nasal CT between 2 h of N95 mask use and 15 min after removal of the mask were statistically significant (p < 0.05 for each). CONCLUSION: Hypercapnia due to prolonged use of the N95 mask may cause choroidal hemodynamic changes and transient increased choroidal thickness.