Visual Interpretation of Vocal Fold Paralysis in Flexible Laryngoscopy Using Eye Tracking Technology

Objectives

Interpretation of laryngoscopy is an important diagnostic skill in otolaryngology. There is, however, limited understanding of the specific visual strategies used while assessing flexible laryngoscopy video. Eye-tracking technology allows for objective study of eye movements during dynamic tasks. The purpose of the present study was to explore visual gaze strategies during laryngoscopy interpretation of unilateral vocal fold paralysis (UVFP) across clinician experience from novice to expert.

Methods

Thirty individuals were shown five flexible laryngoscopy videos, each 10 seconds long. After viewing each video, participants reported their impressions of “left vocal fold paralysis,” “right vocal fold paralysis,” or “no vocal fold paralysis.” Eye tracking data were collected and analyzed for duration of fixation and number of fixations on select areas of interest (AOI). Diagnostic accuracy and visual gaze patterns were compared between novice, experienced, and expert groups.

Results

Diagnostic accuracy among learners in the novice group was significantly lower than those in the more experienced groups (P = 0.04). All groups demonstrated similar visual gaze patterns when viewing the video with normal bilateral vocal fold mobility, spending the greatest percentage of time viewing the trachea. There were differences among groups when viewing the videos of left or right VFP, but the trachea was always in the top three structures for greatest fixation duration and highest number of fixations.

Conclusions

Eye-tracking is a novel tool in the setting of laryngoscopy interpretation. With further study it has the potential to be useful for the training of otolaryngology learners to improve diagnostic skills.