Effect of personal protection equipment (PPE) and the distance from the eye piece of surgical microscope on the field of vision; an experimental study

Iyer, A. , Tikka, T., Calder, N., Qamar, S. N. and Chin, A. (2020) Effect of personal protection equipment (PPE) and the distance from the eye piece of surgical microscope on the field of vision; an experimental study. Otology and Neurotology, 42(4), pp. 606-613. (doi: 10.1097/mao.0000000000002989) (PMID:33156238) (PMCID:PMC7968955)

Abstract

Background: During the Covid-19 pandemic, otolaryngologists are at risk due to aerosol-generating procedures such as mastoidectomy and need enhanced personal protective equipment (PPE). Eye protection can interfere with the use of a microscope due to a reduction in the field of vision. We aimed to study the effect of PPE on the microsurgical field. Methods: Five surgeons measured the visual field using digital calipers at different power settings. They were done with no PPE, a surgical mask, FFP3 mask (N99), and with the addition of small goggles, large vistamax goggles, vistamax plus a face shield, and only a face shield. The measurements were repeated with rings of 5 mm increments. We also measured the “eye relief” of the microscope which is the ideal distance for maximum field of view. Results: There was no major reduction of the field with the surgical or FFP3 mask. But even simple goggles reduced the field up to 31.6% and there were progressive reductions of up to 75.7% with large goggles, 76.8% when a face shield was added, and 61.9% when only face shield was used. The distance rings more than 5 mm also affected the field of view. The eye relief of our eyepiece was found to be 15 mm. Conclusion: The current PPE eye protection is not compatible with the use of a microscope. There is scope for research into better eye protection. Mitigation strategies including barrier drapes and alternative techniques such as endoscopic surgery or use of exoscopes should also be considered.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Calder, Mr Nicholas and Iyer, Mr Arunachalam and Chin, Mr Andy
• Authors: Iyer, A., Tikka, T., Calder, N., Qamar, S. N., and Chin, A.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Otology and Neurotology
• Publisher: Wolters Kluwer
• ISSN: 1531-7129
• ISSN (Online): 1537-4505
• Published Online: 04 November 2020
• Copyright Holders: Copyright © 2020, Otology and Neurotology, Inc.
• First Published: First published in Otology and Neurotology 42(4):606-613
• Publisher Policy: Reproduced in accordance with the publisher copyright policy