The Impact of Tape Sealing Face Masks on Visual Field Scores in the Era of COVID-19: A Randomized Cross-over Study

Precis: Tape sealing of the face mask can prevent fogging artifacts of visual field testing. Here, we demonstrate that tape sealing can improve visual field scores even when fogging artifacts are not obvious. Purpose: The purpose of this study was to demonstrate that visual field scores improve when the face masks are taped to prevent fogging artifacts. Methods: A Single-center, randomized 2x2 cross-over study. Twenty-six visual fields of 13 patients of the glaucoma outpatient clinic were included. Patients were randomized in either sequence 1 (Octopus visual field examination without tape sealing, followed by examination with tape sealing) or sequence 2 (examination with, followed by without tape sealing). Results: The results for mean defect and square root of loss variance differ significantly in the examination with and without tape sealing [mean difference (without-with) 0.39 dB, 95% confidence interval: 0.07-0.70 dB, P=0.018 and 0.49 dB, 95% confidence interval: 0.19-0.79 dB, P=0.003, respectively]. There was no sequence effect (P=0.967) for mean defect nor the square root of loss variance (P=0.779). A significant effect for period (P=0.023) for mean defect was yielded. Conclusion: Tape sealing of face masks during visual field testing prevented fogging artifacts and improved visual field scores even when fogging artifacts were not obvious and should be considered in clinical practice.