Objectively Measuring Observer Attention in Severe Thyroid-Associated Orbitopathy: A 3D Study

Objective: Measure the attentional distraction of facial deformity related to severe thyroid-associated orbitopathy using three-dimensional (3D) images and eye-tracking technology. Methods: Observers recruited at an academic tertiary referral center viewed 3D facial images of patients with severe thyroid-associated orbitopathy (TAO) and controls without TAO. An infrared eye-tracking monitor recorded their eye movements and fixations in real time. Multivariate Hotelling's analysis, followed by planned posthypothesis testing, was used to compare fixation durations for predefined regions of interest, including the eyes, nose, mouth, central triangle, and remaining face without the central triangle between severe TAO patients and controls. Results: One hundred sixteen observers (mean age 26.4 years, 51% female) successfully completed the eye-tracking experiment. The majority of their attention was directed toward the central triangle (eyes, nose, mouth). On multivariate analysis, there were significant differences in the distribution of attention between control and severe TAO faces (T ² = 49.37; F(5,922) = 9.8314, P < 0.0001). On planned posthypothesis testing, observers attended significantly more to the eyes (0.77 seconds, P < 0.0001, 95% confidence interval [CI], 0.51, 1.03 seconds) and less to the nose (−0.42 seconds, P < 0.0001, 95% CI, −0.23, −0.62 seconds) in severe TAO patients. There was no significant difference in time spent on the mouth, the total time spent on the central triangle, or time spent in the remaining face between the two groups. Conclusion: Severe TAO distracted observer attention toward the eyes compared to control patients. These data lend insight into how TAO may alter observers' perceptions of these patients. Future studies should investigate how these changes in observer gaze patterns may reflect the social perception of TAO patients. Level of Evidence: NA Laryngoscope, 129:1250–1254, 2019.