Face mask-related fogging may skew glaucoma testing results
Researchers found that poorly fitted face masks can cause visual field artifacts that may be misinterpreted during standard automated perimetry as glaucoma progression or low test reliability.
“The COVID-19 pandemic has impacted all aspects of eye care, including glaucoma practice, in several ways, and these effects can cause unintended consequences,” Nurettin Bayram, MD, from the University of Health Science, Kayseri City Training and Research Hospital in Kayseri, Turkey, and colleagues wrote. “The use of face masks causes additional problems in obtaining reliable perimetry results, especially if poorly fitting face masks are not adequately sealed.”
To investigate the impacts of face mask use on standard automated perimetry (SAP), Bayram and colleagues evaluated 127 patients with glaucoma. Among those, 101 wore ear-loop surgical face masks, and 26 patients wore ear-loop cloth face masks with no nose wires.
Face mask-related low SAP reliability occurred in 23 patients, and lower visual field defects occurred in three patients. Low SAP reliability was higher among those who wore cloth face masks compared with surgical face masks (47.8% vs. 9.9%; P = .0001). Among these patients, the visual field technicians noted inappropriate face mask position in two patients and face-mask related fogging on the perimeter lens in 13 patients at the end of testing. Nine of those patients wore eyeglasses.
The presence of mask-related eyeglass fogging, which occurred in 28 of 84 patients who wore glasses, correlated with a predictive value for low SAP reliability (P = .0001). After taping the upper edge of masks to the nose bridge, the researcher observed improvements in fixation losses and false-positive errors (P = .001).
“After this study was concluded, we routinely started bandaging the face masks in the appropriate position for all patients who underwent the SAP in our clinic,” Bayram and colleagues wrote. “The face mask-related low SAP reliabilities only increase the workload and primarily cause fixation losses and false-positive errors. These problems can be solved easily with the method mentioned above.”
Perspective
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Life is decidedly different in the COVID-19 era. Over the past year we’ve become accustomed to isolating at home, washing hands frequently, keeping our distance from others and wearing masks in public. Our practices were hit hard immediately with closure. Shortly thereafter, we were able to reopen, but with restrictions that may affect patient care.
Bayram and colleagues in their single-center prospective observational study report on what most of us have come to learn. It’s more difficult to get good visual field data when patients wear masks. Specifically, they found that paper “procedure” masks work better than cloth masks, better fitting masks are less likely to produce artifacts, and lens fogging negatively affects visual field results. Eyeglass fogging is a good predictor of trial lens fogging, and taping the top of the mask solves the problem. While it’s good to confirm and quantify these problems, if you find these results surprising, you haven’t been paying attention.
I’ll close on a more general note. Times are hard, and people are suffering. Take a bit of time to talk with your patients. Most people have been isolated, and a bit of human kindness may be just what the doctor ordered.
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