Visual Acuity During Direct Laryngoscopy at Different Illuminance Levels

Show simple item record Baker, Paul en Raos, AS en Thompson, John en Jacobs, Robert en
dc.coverage.spatial United States en 2013-11-28T01:28:29Z en 2015-02-13T03:38:42Z en 2013-02 en
dc.identifier.citation Anesthesia and Analgesia, 2013, 116 (2), pp. 343 - 350 en
dc.identifier.issn 0003-2999 en
dc.identifier.uri en
dc.description.abstract Adequate light is essential for vision during direct laryngoscopy. The ISO 7376:2009 standard specifies the minimal illuminance for laryngoscopes. No studies have objectively examined the relationship between laryngoscope illumination and visual acuity during laryngoscopy. METHODS:: We measured the near visual performance of 50 anesthesiologists during direct laryngoscopy using near vision charts located at the larynx of 4 manikins. A variable voltage supply adjusted the illuminance from the laryngoscope to 50 lux, 200 lux, 700 lux, and 2000 lux. Participants also rated their experience regarding brightness of the laryngoscope, clarity of view, visual performance, and suitability and adequacy of the light, before proceeding to the next manikin with a different light level. The distance visual performance of the participants was also measured using standard letter acuity wall charts at the same light levels. RESULTS:: Visual acuity in manikins and on wall charts was associated with an increasing lux level (P < 0.0001). Visual acuity was lower at 50 lux and 200 lux compared with 700 lux by significantly more than the clinically discernible 0.1 logMAR. No statistically significant improvement in visual acuity occurred when illuminance was increased to 2000 lux. The mean (standard deviation) logMAR scores at the 4 chosen lux levels on the manikin charts were: 50 lux 0.05 (0.13), 200 lux 0.06 (0.10), 700 lux-0.05 (0.11), and 2000 lux-0.07 (0.11). This result was unaffected by age, seniority, subspecialty, history of difficulty focusing, or use of lenses for laryngoscopy. Subjective rating of laryngoscope brightness favored 2000 lux for clarity of view, suitability of the light for laryngoscopy, and visual performance. The average observation distance for direct laryngoscopy was 32 cm. CONCLUSIONS:: Visual acuity improves as the laryngoscope illuminance increases up to 700 lux. No statistically significant improvement was measured by increasing the illuminance up to 2000 lux. Subjectively, anesthesiologists favor illuminance of 2000 lux for direct laryngoscopy. en
dc.language Eng en
dc.relation.ispartofseries Anesthesia and Analgesia en
dc.relation.replaces en
dc.relation.replaces 2292/21154 en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. Details obtained from en
dc.rights.uri en
dc.subject Adult en
dc.subject Confidence Intervals en
dc.subject Contrast Sensitivity en
dc.subject Female en
dc.subject Humans en
dc.subject Laryngoscopy en
dc.subject Lighting en
dc.subject Linear Models en
dc.subject Male en
dc.subject Manikins en
dc.subject Middle Aged en
dc.subject Vision Tests en
dc.subject Visual Acuity en
dc.title Visual Acuity During Direct Laryngoscopy at Different Illuminance Levels en
dc.type Journal Article en
dc.identifier.doi 10.1213/ANE.0b013e318273f397 en
pubs.issue 2 en
pubs.begin-page 343 en
pubs.volume 116 en
dc.identifier.pmid 23302969 en
pubs.end-page 350 en
dc.rights.accessrights en
pubs.subtype Article en
pubs.elements-id 371866 en Medical and Health Sciences en Optometry and Vision Science en School of Medicine en Anaesthesiology en Paediatrics Child & Youth Hlth en
dc.identifier.eissn 1526-7598 en
dc.identifier.pii ANE.0b013e318273f397 en
pubs.record-created-at-source-date 2013-11-28 en
pubs.dimensions-id 23302969 en

Files in this item

There are no files associated with this item.

Find Full text

This item appears in the following Collection(s)

Show simple item record


Search ResearchSpace