Abstract
Purpose :
The objective of the study was to determine the wetting properties of lotrafilcon B lenses packaged with copolymer 845 and an added block copolymer (EOBO-41) using in vitro and in vivo methods.
Methods :
Study 1: Senofilcon C, samfilcon A, lotrafilcon B/copolymer 845 (LOTRA-B1) and lotrafilcon B/copolymer 845+EOBO-41 (LOTRA-B2) silicone hydrogel lenses (n=10) were pre-soaked in PBS for 16 hrs and then placed on a pedestal for Interfacial Dewetting and Drainage Optical Platform (iDDrOP) wettability measurement [1]. Lenses were submerged in fresh PBS and then raised through the air interface to dewet. A video of the dewetting allows objective water break-up time (WBUT) and water retention time (from 100% to 90% break-up) measurements. Study 2: Lotrafilcon B/copolymer 845 +EOBO 41 lenses were worn by 45 subjects (90 eyes) for 30 days and cared for with Clear Care®. The pre-contact lens tear film was recorded during the full inter-blink period using the Tearscope and a digital video recording system after insertion, 8hrs and 12hrs on Day 1 and after 8hrs on Day 30. The tear film kinetics were characterized by the Minimum Protected Area (MPA) between two natural blinks.
[1] Bhamla, JCIS, 2015
Results :
Study 1: LOTRA-B2 lenses had a significantly longer WBUT (19±6 sec) and water retention time (1.1±0.5 sec) than the other lens types tested (WBUT’s of 14±2 sec, 14±4 sec and 15±5 sec and water retention times 0.7±0.2 sec, 0.7±0.3 sec and 0.6±0.3sec for LOTRA-B1, senofilcon C and samfilcon A respectively; p<0.05). Study 2: The mean MPA on Day 1 was as follows: insertion 86.8%, 8hrs 91.0% and 12hrs 91.2% [mean difference for 8hrs vs. insertion 4.1%; 95% CI (-0.75, 8.89) and for 12hrs vs. insertion 4.4%; 95% CI (-0.43, 9.23)]. The mean MPA at Day 30 8rs was 86.9% [mean difference for Day 30 8hrs vs. Day 1 8hrs -4.0%; 95% CI (-8.94, 0.87)].
Conclusions :
The in vitro wetting properties of lotrafilcon B lenses packaged in copolymer 845+ EOBO-41, characterized by air interface dewetting, were superior to those of lotrafilcon B/copolymer 845, senofilcon C, and samfilcon A. The in vitro resistance to dewetting of lenses packaged with EOBO-41 was associated with maintenance of in vivo wettability over a full 12hrs of wear on a single day and over 30 days of wear.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.