Conclusion
This study demonstrates that PPE including an FFP-3 mask and full-face visor is incompatible with use of the operating microscope; the view of the surgical field was reduced to below 10% in most cases. Urgent consideration needs to be given to solutions that allow for concurrent use of the operating microscope and drill that are required for mastoid surgery, whilst affording the surgeon adequate protection from viral transmission in the COVID-19 era.