OCT-Angiography Face Mask-Associated Artifacts During the COVID-19 Pandemic.

PRCIS: Face mask wearing has no significant effects on artifacts or vessel density measurements in optic nerve head (ONH) and macular optical coherence tomography-angiography (OCT-A) scans. PURPOSE: The aim was to assess the difference in area of artifacts observed in optical OCT-A scans with and without face mask wear and to verify if mask wear interferes with OCT-A vessel density measurements. SUBJECTS AND CONTROLS: A total of 64 eyes of 10 healthy subjects, 4 ocular hypertensive, 8 glaucoma suspects, and 17 glaucoma patients were included. MATERIALS AND METHODS: High-density ONH and macula OCT-A scans were obtained in patients with and without surgical masks. Seven different artifacts (motion, decentration, defocus, shadow, segmentation failure, blink, and Z-offset) were quantitatively evaluated by 2 trained graders. The changes in the area (% of scan area) of artifacts, without and with mask wearing, and differences of vessel density were evaluated. RESULTS: Trends of increasing motion artifact area for the ONH scans [4.23 (-0.52, 8.98) %, P=0.08] and defocus artifact area for the macular scans [1.06 (-0.14, 2.26) %, P=0.08] were found with face mask wear. However, there were no significant differences in the mean % area of any artifacts (P>0.05 for all). Further, the estimated mean difference in vessel density in images acquired without and with masks was not significant for any type of artifact. CONCLUSION: Face mask wearing had no significant effect on area of artifacts or vessel density measurements. OCT-A vessel density measurements can be acquired reliably with face mask wear during the pandemic.

Visual Field Artifacts in Glaucoma With Face Mask Use During the COVID-19 Pandemic.

PURPOSE: The coronavirus (COVID-19) pandemic has changed how outpatient care is delivered in ophthalmology clinics, particularly with glaucoma care. This case series highlights the need for awareness of fogging and improper face mask fit as causes of standard automated perimetry artifacts in patients with ocular hypertension and glaucoma. CLINICAL PRESENTATIONS: Six patients with the diagnosis of ocular hypertension, glaucoma suspect, or glaucoma underwent standard automated perimetry (24-2 or 10-2 SITA, Humphrey Field Analyzer) while wearing ear-loop surgical face masks. Due to patient complaints of fogging during the testing, low test reliability, and unexpected results, the tests were repeated after taping securely the mask to the bridge of the nose. CLINICAL FINDINGS: Fogging may reduce visual field (VF) test reliability and induce artifacts that mimic glaucomatous defects. VF test reliability can be improved and artifacts minimized following mask taping. In 1 case there was worsening of VF defects after mask taping. This suggests that fogging may also disguise true VF defects. CONCLUSIONS: Fogging can result in unreliable VF testing with glaucoma-like artifacts. Secure taping of the face mask to the nose bridge may minimize this problem and reduce unnecessary additional testing and follow-up visits.