Purpose: Non-invasive tear break up time (NITBUT) is a test commonly used by clinicians to measure the stability of the tear film. This study aims to compare the NITBUT of the Bausch and Lomb Biotrue Oneday (BT) Daily Disposable contact lenses against 3 other commercially available daily disposable lenses to see if BT can provide a more stable pre-lens tear film over the other 3 types of lenses at 12 hours of lens wear. Methods: Twelve existing contact lens wearers were recruited to wear 4 types of contact lenses each for a day of at least 12 hours. Other than BT, the other 3 test lenses were the daily disposable lenses made of etafilcon A (AV), narafilcon A (TE) and delefilcon A (DT1) materials. Each subject was assigned the lenses without knowing the brand of the lenses. Baseline NITBUT was first measured with no lens in the eye and pre-lens NITBUT was measured again at 12 hours after the lenses were worn. The NITBUT was measured using Oculus Keratograph 5M. This instrument measures the NITBUT objectively using infrared illumination which is invisible to the human eye and can prevent glare or bright light irritation during examination. Results: NITBUT was provided by the instrument as “first break” and “average break” values. In this study, the first break value was analyzed because that was the time when the break-up of tears was first detected by the instrument, and that matches with what the clinicians normally do in measuring NITBUT. The NITBUT for the nesofilcon A lens (BT) was longer than that for all the other 3 lens types in 10 out of the 12 subjects (83%). The mean TBUT for BT, AV, TE, DT1 was respectively 17.9 ± 4.3 sec, 9.5 ± 3.3 sec, 8.3 ± 5.9 sec and 8.8 ± 3.6 sec. Not only is the difference in NITBUT statistically significant (p<0.05, paired t-test – nesofilcon A (BT) Vs each of the 3 lens types), but also the NITBUT for BT is about double than that for all the other 3 types of lenses. Conclusion: The NITBUT for the nesofilcon A lens (BT) measured at 12 hours was about double than that for the other 3 lens types and the difference was statistically significant. The results suggested that the Biotrue Oneday provides a more stable pre-lens tear film than the other 3 types of daily disposable lenses at 12 hours of lens wear.

목 적: 소프트 콘택트렌즈 착용자를 대상으로 fully integrated printing 공법으로 제조된 매일 교체용 써클 콘택트렌즈를 착용하게 한 후 소프트 콘택트렌즈 착용 시 나타난 증상과 써클 콘택트렌즈 착용 시 나타난 증상을 비교하였다. 방법: 소프트콘택트렌즈 착용자 36명(21.35±1.18세)이 연구에 참여하였다. 각막곡률은 자동곡률계(Canon RK-F1)로 측정하였고, 구결막충혈, 윤부충혈, 각·결막 염색, 각막부종 및 검결막 유두의 발생 정도를 CCLRU grading scale에 따라 세극등으로 검사하였으며 자각적 증상은 CCLRU grading scale에 따라 증상의 정도와 빈도를 측정하였다. 각각의 검사는 소프트 콘택트렌즈 착용 후, 써클 콘택트렌즈 착용 4주일 후에 측정하고 비교하였다. 써클 콘택트렌즈의 표면은 주사현미경(Hitachi S-4700)을 사용하여 표면 거칠기를 관찰하였다. 결 과: 매일교체용 써클 콘택트렌즈 착용 4주일 후 각막곡률에 변화는 없었다. 자각적증상은 감소하였고, 특히 ``모래가 들어간 느낌``과 이물감 및 구결막충혈 및 윤부충혈은 통계적으로 유의하게 감소하였다. 그러나 각막염색, 구결막염색, 검결막염색 및 결막유두는 임상적으로 정상적인 수준이었지만(평균: 0.44~ 0.78) 써클 콘택트렌즈 착용 후 유의하게 증가하였다(p