Purpose:
To assess the surface wettability and deposition characteristics of a novel CL material compared to commercially available daily disposable contact lenses using sessile drop contact angle and chromatographic techniques.
Methods:
The sessile drop contact angle was measured by dispensing a 0.6µL droplet of water onto a blotted anterior lens surface of a novel lens material, narafilcon B (AV TruEye) and etafilcon A (AV Moist). The contact angle was measured at two different points on each lens, resulting in four to six data points for each type of lens in each experiment. Lenses were analyzed both directly out of the packaging solution without rinsing, as well as after being soaked for 18 hours in an artificial tear fluid (ATF) containing common lipids and proteins to simulate lens wear. Quantification of lipid and protein deposits on the lenses soaked in the ATF was performed using GC and HPLC methods.
Results:
The test lens material demonstrated a more wettable surface based on a statistically significantly lower sessile drop water contact angle than both narafilcon B (p = 9.60 x 10-5) and etafilcon A (p = 5.88 x 10-6) directly out of the blister. After soaking in ATF, the test lens material had a statistically significantly lower contact angle than narafilcon B (p = 2.34 x 10-3) and etafilcon A (p = 6.25 x 10-6). The test lens material also demonstrated the lowest overall deposition level after overnight exposure to an ATF. GC and HPLC demonstrated 13 µg/lens combined lipids and proteins were deposited on the test lens material, which is statistically significantly lower than the 90 µg/lens (p = 7.39 x10-6) deposited on narafilcon B and 33 µg/lens (p = 2.81 x10-5) deposited on etafilcon A.
Conclusions:
Based on sessile drop contact angle analysis, the test lens was statistically significantly more surface wettable than either narafilcon B or etafilcon A. The test lens also had statistically significantly fewer combined lipid and protein deposits after being soaked in an artificial tear fluid for 18 hours than either the narafilcon B and etafilcon A. Lower total deposition on lenses may contribute to lower contact angles and enhanced wettability and comfort at end of day.