Eye tracking as a proxy for perceptual evaluation of repaired cleft lip

Human interactions begin with near-instantaneous visual evaluation of the face, modifying emotional responses and social behavior toward the person. Eye-tracking technology can provide a potential window into how humans undertake this evaluation, and the threshold of whether a face containing a craniofacial difference is perceived as ‘‘normal.’’ This study’s main questions were whether gaze patterns differ from normal when evaluating children with craniofacial differences, and whether these gaze patterns vary with different levels of craniofacial deformity. Two experiments tested the feasibility of using eye tracking to study facial evaluation and whether there was a difference in the gaze pattern and characteristics, correlating with the Asher McDade Aesthetic Index. Fifty-three participants’ eye movements were recorded as they gazed at photographs of children either with hemifacial microsomia or repaired cleft lip, with repaired cleft lip digitally corrected to symmetry, or with no craniofacial disorder. Recruitment and participation for this study occurred in a pediatric plastic surgery clinic and in a medical school student center. Participants gazed longer on the lip in the cleft-lip photographs compared with control photographs in the first experiment (207 ms; SD 75 versus 145 ms; SD 61, respectively; P ¼ 0.04). This gaze bias was confirmed in the second experiment and found to correlate with severity (r ¼ 0.042). Gaze patterns differ when individuals look at photographs with or without craniofacial differences. The degree to which these eye movement patterns differ correlates with the severity of craniofacial deformity.