In vitro water wettability of silicone hydrogel contact lenses determined using the sessile drop and captive bubble techniques

Abstract

This study investigated the water contact angles of five commercially available silicone hydrogel contact lenses (Acuvue Advance, Acuvue Oasys, Focus Night & Day, O2 Optix, and PureVision) using sessile drop and captive bubble techniques. The only lens type that showed a significant difference in water contact angle when measured by sessile drop direct from the blister compared with after 48 h of soaking/washing in saline was the Acuvue Advance lens (from 66 degrees to 96 degrees, respectively) (p=0.0002), presumably because of surface active agents within the blister solution. The water contact angle data split the lenses into two distinct groups (p<or=0.002). The Acuvue Advance, Acuvue Oasys, and PureVision lenses demonstrated relatively high sessile drop measures and relatively low captive bubble values (thereby displaying significant hysteresis) whereas the Focus Night & Day and O2 Optix lenses showed relatively low sessile drop measures and relatively high captive bubble values (with little hysteresis). Contact angle analysis of hydrogel lens surfaces is highly methodologically dependent and may be able to predict the clinical performance of contact lenses in vivo.