Pupil psychosensory reflex in response to own and standardised silhouettes in patients with anorexia nervosa.

OBJECTIVE

This study aimed to assess the physiological response of patients with anorexia nervosa (AN) to different types of silhouettes using pupillometry.

METHODS

We measured the pupil psychosensory reflex (PSR) of 42 patients with AN and 35 healthy controls in response to standardised body silhouettes and to pictures of their own silhouettes digitally modified to represent different body mass indices (BMI). Perceptual distortion and body dissatisfaction were assessed using Anamorphic Micro Software©. Twenty-three of the recruited patients were tested up to four times during an inpatient treatment programme to assess the impact of weight gain.

RESULTS

PSR correlated with the subjective rating of emotional arousal in controls but not in patients. Own silhouettes and standardised silhouettes triggered a different pupil response both in patients with AN and in controls. With pictures of their own silhouettes, pupil response to underweight stimuli differed from pupil response to normal weight or overweight stimuli in both groups. Weight gain was associated with an increase in PSR, an improvement of ideal BMI and a decrease of body dissatisfaction, but no change in perceptual distortion.

CONCLUSION

Our findings support the idea that pupillometry could be a useful tool to assess the physiological state of patients with AN.