The purpose of this study was to measure the advancing and receding contact angles (CAs) of five daily disposable (DD) lenses and the osmolality, surface tension (ST), and pH of each blister pack solution.
The advancing and receding CAs were measured directly out of the blister pack for five DD lenses: omafilcon A (CooperVision), nelfilcon A (CIBA Vision), modified nelfilcon A (CIBA Vision), etafilcon A (Johnson & Johnson), and narafilcon A (Johnson & Johnson). Advancing CAs were measured using sessile drop and Wilhelmy balance methods. Receding CAs were measured using the Wilhelmy balance method. ST, pH, and osmolality were measured for each blister pack solution from all the DD lenses.
The advancing CAs for the nelfilcon A lenses were statistically lower (P<0.05) than the advancing CAs of the other three lenses. The receding CAs for etafilcon A were statistically lower (P<0.05) than the receding CAs for the other four lenses. The pH of all the blister pack solutions was relatively neutral (7.01–7.43). The ST of the blister pack solution for the modified nelfilcon A was significantly lower (P<0.05) than the ST of all other blister pack solutions. The osmolality of the blister pack solutions for the etafilcon A and narafilcon A lenses were significantly higher (P<0.05) than the other blister pack solutions.
The modified nelfilcon A lens had low advancing CAs and low receding CAs showing minimal hysteresis. The blister pack solution for the modified nelfilcon A lens had the lowest ST, a low osmolality, and a neutral pH.
From the Centre for Contact Lens Research (K.L.M., L.J.), University of Waterloo, Waterloo; Institute of Medical Science (R.R.), University of Toronto; and Department of Ophthalmology and Vision Sciences (R.R.), Toronto Western Hospital, Toronto, ON, Canada.
Supported by Canadian Optometric Education Trust Fund (to K.L.M.) and NSERC, Canada (to L.J.).
Address correspondence and reprint requests to Kara Menzies, B.Sc., University of Waterloo, School of Optometry, 200 University Ave. W, Waterloo, ON, Canada N2L 3G1; e-mail: firstname.lastname@example.org
Accepted October 12, 2009.