Measuring Outcomes of Mohs Defect Reconstruction Using Eye-Tracking Technology.

Abstract

Objectively measuring how Mohs defect reconstruction changes casual observer attention has important implications for patients and facial plastic surgeons. To use eye-tracking technology to objectively measure the ability of Mohs facial defect reconstruction to normalize facial attention. This observational outcomes study was conducted at an academic tertiary referral center from January to June 2016. An eye-tracking system was used to record how 82 casual observers directed attention to photographs of 32 patients with Mohs facial defects of varying sizes and locations before and after reconstruction as well as 16 control faces with no facial defects. Statistical analysis was performed from November 2018 to January 2019. First, the attentional distraction caused by facial defects was quantified in milliseconds of gaze time using eye tracking. Second, the eye-tracking data were analyzed using mixed-effects linear regression to assess the association of facial defect reconstruction with normalized facial attention. The 82 casual observers (63 women and 19 men; mean [SD] age, 34 [12] years) viewed control faces in a similar and consistent fashion, with most attention (65%; 95% CI, 62%-69%) directed at the central triangle, which includes the eyes, nose, and mouth. The eyes were the most visually important feature, capturing a mean of 60% (95% CI, 57%-64%) of fixation time within the central triangle and 39% (95% CI, 36%-43%) of total observer attention. The presence of Mohs defects was associated with statistically significant alterations in this pattern of normal facial attention. The larger the defect and the more centrally a defect was located, the more attentional distraction was observed, as measured by increased attention on the defect and decreased attention on the eyes, ranging from 729 (95% CI, 526-931) milliseconds for small peripheral defects to 3693 (95% CI, 3490-3896) milliseconds for large central defects. Reconstructive surgery was associated with improved gaze deviations for all faces and with normalized attention directed to the eyes for all faces except for those with large central defects. Mohs defects are associated with altered facial perception, diverting attention from valuable features such as the eyes. Reconstructive surgery was associated with normalized attentional distraction for many patients with cutaneous Mohs defects. These data are important to patients who want to know how reconstructive surgery could change the way people look at their face. The data also point to the possibility of outcomes prediction based on facial defect size and location before reconstruction. Eye tracking is a valuable research tool for outcomes assessment that lays the foundation for understanding how reconstructive surgery may change perception and normalize facial deformity.