목 적: 1일 착용용 소프트 콘택트렌즈의 가파르게 처방된 정도에 따른 각막굴절력의 변화, 눈물막 파괴 시간의 변화, 안압의 변화와 상관관계를 알아보고자 하였다. 방 법: 대학생 24명(48안)을 대상으로 1일착용 렌즈를 8시간 착용시켜 8시간 경과 후 렌즈를 제거하고 각막굴절력, 눈물막 파괴시간 그리고 안압 측정을 시행하여 콘택트렌즈 착용전과 비교하였다. 결 과: 가파른 피팅을 함에 따라 각막굴절력은 +0.29±0.06 D 증가(t=-12.62, p<0.05)하였으며, 눈물 띠 파괴시간(TBUT)은 –1.26±2.02sec 감소(t=5.04, p<0.05)하였으며 안압은 –2.19±2.15mmHg 감소 (t=6.4, p<0.05)하였다. 가파른 피팅 정도에 따른 각막의 굴절력과의 상관관계(r=-0.98)는 강한 음의 상관 관계를 가졌으며. TBUT와의 상관관계(r=-0.26)는 약한 음의 상관관계를 가졌으나 안압(r=-0.07)과는 상관 관계가 없었다. 결 론: 각막의 곡률반경에 비하여 소프트 콘택트렌즈의 곡률반경이 0.3mm 이상 가파른 피팅되어 8시 간 착용했을 때, 각막굴절력의 변화에 대한 강한 상관관계가 있으므로 소프트 콘택트렌즈 처방 시 가파른 피 팅이 되지 않도록 유의해야 한다.

Purpose: This study was to assess the influence of silicone hydrogel contact lenses wearing time on corneal higher-order aberrations (HOAs), visual performance, and subjective ocular symptoms. Methods: Thirty subjects took part in this study. Subjects were fitted with silicone hydrogel contact lenses (Biofinity). Best-corrected visual acuity (VA) at two contrast levels (100% and 10%) and best-corrected contrast sensitivity (CS) for four spatial frequencies (3, 6, 12, and 18 cycles per degree) were measured under photopic and mesopic conditions. Corneal HOAs were measured with 4-mm and 6-mm pupils using Wavefront Analyzer. All measurements were performed respectively after 2 hours and 9 hours wear with the silicone hydrogel lenses during a day. Subjects were asked by a study examiner to complete the questionnaire for contact lens-related subjective ocular symptoms. Results: Data for this study were employed for fifty-four eyes (27 subjects; 14 females, 13 males) and the subjects were 24.30 ± 2.96 years. For the subjects, current or previous experience with contact lenses was 23 subjects and non-experience with contact lenses was 4 subjects. Regarding visual quality under photopic and mesopic conditions, there was no statistically significant difference in high contrast and low contrast visual acuity as well as contrast sensitivity between 2 hours and 9 hours wear. For corneal HOAs, we also did not find any significant changes in total HOAs, third-order, fourth-order, coma, and spherical aberration for both 4-mm and 6-mm pupils between the two wearing time. In the relative frequency of contact lens-related subjective ocular symptoms, there were statistically differences in discomfort, dryness, and closing eyes between 2 hours and 9 hours wear within the brand (p=0.031, p=0.001, and p=0.031, respectively) (after 9 hours of the lens wear, discomfort (52%), dryness (74%), and closing eyes (56%)); however, there were no significant differences in changeable vision and removing lenses between the two wearing time. Conclusions: Silicone hydrogel contact lenses used this study do not reduce optical quality of the eye and visual quality after nine hours of the contact lens wear during a day. However, the majority of soft contact lens wearers still encounter clinically significant ocular symptoms including discomfort and dryness with the silicone hydrogel lenses.