Difference in Rotation Pattern of Toric Soft Contact Lenses with Different Axis Stabilization Design

Abstract

Purpose: It was investigated whether two different stabilization designs of toric contact lenses changed the rotational axis and degree of toric lenses according to body posture and gaze direction in the present study. Methods: Toric soft contact lenses with Lo-Torque TM design and ASD design (accelerated stabilized design) were fitted on 52 eyes aged in 20s-30s. Then, rotational degree was measured at the five gaze directions including front gaze and the lying position. Results: When gazing the front and vertical directions in the upright posture, lens was much rotated to nasal side for the Lo-Torque TM design and temporal side for the ASD design. When gazing horizontal direction, both design lenses were rotated against to the gaze direction. Rotation degree was the smallest at superior direction gaze and the largest at nasal gaze. In case of the rotation degree less than 5 o , Lo-Torque TM design was more frequent when gazing front and vertical directions, and ASD design was more frequent when gazing horizontal direction. In addition, the lens with Lo-Torque TM design was lesser rotation degree than with ASD design immediately after lying. On the other hand, the lens with ASD design was lesser rotation degree than with Lo-Torque TM design 1 minute later after lying. Conclusions: This study confirmed that axis rotation of the lens induced by gaze direction and posture was different according to axis stabilization design during wearing toric soft contact lens.