Carotid blood flow in abnormal head posture: a prospective observational study exploring facial asymmetry in strabismus.

Purpose: To investigate whether abnormal head posture (AHP) induces changes in common carotid artery blood flow (CCBF), thereby leading to the development of facial asymmetry in the setting of strabismus and ocular torticollis.

Methods: This was a prospective observational study of pediatric subjects in an urban ophthalmology clinic who underwent bilateral carotid artery ultrasound examination with spectral Doppler in an upright, straight-head posture and with a head tilt of 30°-45° to the right and left. The primary outcome was change in carotid flow on the side of the head tilt.