Abstract
Purpose :
The major route of infection of SARS-CoV-2 is supposed to be the respiratory way. Thus, mouth-nose masks are requested to prevent the viral transmission. The aim of the present study was to investigate, if wearing a mouth-nose mask impaired visual field function in normal eyes.
Methods :
30 healthy eyes of 30 subjects were recruited. Visual field function was tested by white-on-white perimetry (OCTOPUS 900; 90°). Sensitivity thresholds were analysed in 14 defined test points (P1-P14, inferior visual field) under 3 different test conditions while wearing a nose-mouth mask: (I) position 1: 1.5cm under the lower eyelid, nose clip not used; (II) position 2: 1.5cm under the lower eyelid, nose clip correctly positioned; (III) position 3: 0.5 cm under the lower eyelid, nose clip correctly positioned. All data were compared to sensitivity thresholds without wearing a nose-mouth mask (reference). Mean D was calculated as difference between each test condition and reference, respectively. The study was approved by the local ethics committee and was done in accordance with the tenets of the Declaration of Helsinki. Informed consent was obtained from each participant.
Results :
Mean sensitivity was not significantly different between all three test conditions (26.6±2.4 dB (I); 28.3±2.4 dB (II); 27.8±2.2 dB (III) and reference (28.5±2.4 dB), respectively. Subgroup analysis for test points P1-P14 yielded significantly different sensitivity thresholds between test condition (I) and reference at test point P3 – P12 (p≤0.005). Sensitivity thresholds at test point P7 were significantly different between test condition (II) and (III) compared to reference (p<0.001), respectively. Mean D increased while wearing a mask at P7 in test condition (II) < (III) < (I) (-8.3±7.3 dB; -11.3±9.5 dB; -20.1±7.6 dB).
Conclusions :
Visual field function was significantly impaired inferior-nasal while wearing a nose-mouth mask in normal eyes, especially if the nose clip was not used correctly.
This is a 2021 ARVO Annual Meeting abstract.