Effect of using prismatic eye lenses on the posture of patients with adolescent idiopathic scoliosis measured by 3-D motion analysis

This is a preliminary investigation to detect the body sway and postural changes of patients with AIS under different spatial images. Two pairs of low-power prismatic eye lenses (Fresnel prisms) with 5 dioptre and 10 dioptre were used. In the experiment, the apices of the prisms were orientated randomly at every 22.5° from 0° to 360° to test changes. Four patients with mean age of 11 and Cobb's angle of 30° were recruited and the results showed that the low-power prisms at specific orientations (157.5° and 180°) could cause positive postural changes (2.1° - 2.7° reduction of angle of trunk mis-alignment) measured by 3-D motion analysis. This might be used for controlling their scoliotic curves by induced visual bio-feedback. Apart from this laboratory test, a longitudinal study is necessary to investigate the long-term effect of the prisms at different powers and orientations (under both static and dynamic situations) on the patient's posture, spinal muscular activities, vision, eye-hand coordination, psychological state and other daily activities before it becomes an alternative management of AIS.