Abstract
Purpose :
A new contact lens material (NCLM) was designed with a unique phosphoryl choline water gradient surface. This work evaluates the durability and wettability of this water gradient surface after 30 days of on-eye daily wear use.
Methods :
The NCLM (n=5) were worn on a daily wear regimen for 30 days that included nightly manual cleaning (rubbing) and disinfection in OPTI-FREE® RepleniSH®. The control group was out of pack (OOP) lenses (n=5). The lenses were pre-soaked in PBS for 16 hrs and then tested with the Interfacial Dewetting and Drainage Optical Platform (iDDrOP) wettability measurement (Bhamla, 2015), which provides quantitative in vitro surface material property analysis without interference from packaging solution, tears, or patient variation. A video of the lens dewetting in PBS allows objective water break-up time (WBUT) to be collected. The same lenses were then stained using Sudan Black to assess the loss of the gradient surface coating. Staining was analyzed using a custom software that generates a percent stain metric.
Results :
The WBUT for ex vivo lenses (21 ± 5.62 sec) was comparable to the OOP control lenses (27 ± 3.28 sec) even after 30 days of on-eye daily wear, The ex vivo lenses demonstrate significantly higher WBUT compared to the OOP WBUT for other inherently wettable CL: comfilcon A: 6 ± 2 sec, senofilcon A: 9 ± 3 sec, samfilcon A: 15 ± 5 sec, and senofilcon C: 14 ± 4 sec (Fig 1). The staining metric on either group of lenses was less than 1% (ex vivo: 0.12 ± 0.09% vs OOP: 0.43 ± 0.65%) indicating uniform coverage of the hydrophilic water gradient coating. However, for competitor lenses, the staining metric was higher than 10%.
Conclusions :
The surface coating durability of ex vivo CL for a new 30-day wear lens product was comparable to OOP lenses, and the surface wettability was superior to the OOP properties of other inherently wettable CL even after 30 days of on-eye wear. Moreover, the biologically inspired water gradient coating maintains uniform coverage on the lens even after 30 days of daily wear.
This is a 2021 ARVO Annual Meeting abstract.