눈물양에 따른 토릭 소프트콘택트렌즈의 축 회전양 변화

Purpose: The present study was aimed to investigate the effect of tear volume on a change of axial rotation according to wearing time of toric soft contact lens and gaze directions. Method: Toric soft contact lenses with double thin zone design applied on 62 eyes. Then, changes in non invasive tear film break-up time and the rotational direction/amount of lens when changing gaze direction were respectively measured after 15 minutes and 6 hours of lens wear. Results: Lens rotation to temporal direction was more found when changing gaze direction after lens wear. However, its rotation was varied according to wearing time and the subjects’ tear volume. Furthermore, the frequency of lens rotation to temporal direction was higher in dry eyes compared with normal eyes at nearly all gaze directions after 15 minutes and 6 hour of lens wear. The rotational amount of lens was generally greater in dry eyes after 15 minutes of lens wear. However, its difference between normal eyes and dry eyes was not great after 6 hours of lens wear. Conclusion: The present study revealed that axial rotation of toric soft contact lens was varied according to the wearer’s tear volume and lens rotational patterns at the initial, and extending periods of lens wear were different. The change in rotational pattern of toric soft contact lens from these results means the possibility of visual change after extending lens wear, and the identification of its correlation with tear volume suggests the necessity of considering factors for choosing appropriate toric soft contact lens.