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L. M. Harp, B. Fink, G. L. Mitchell, R. M. Hill; Contributions of Silicone Hydrogel Transmissibility and Tear Exchange to Corneal Oxygen Supply. Invest. Ophthalmol. Vis. Sci. 2009;50(13):4274.
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© ARVO (1962-2015); The Authors (2016-present)
The purpose of this study is to evaluate and compare the physiological performance of 4 silicone hydrogel contact lens and 2 rigid lens materials. In particular, the difference in corneal oxygen uptake measured under static and dynamic wearing conditions, which provides an indication of the amount of tear exchange that takes placed with the blink, will be compared.
Corneal oxygen uptake was measured on the right eye of 15 subjects following 5 minutes of static (no blinking) and dynamic (with blinking once every 5 seconds) wear of the following lens materials: Senofilcon A (Vistakon Acuvue Oasys, 14.0 mm diameter), Comfilcon A (Cooper Biofinity, 14.2 mm diameter), Lotrafilcon B (Ciba O2 Optics, 13.2, 14.0, and 14.8 mm diameters), Lotrafilcon (Ciba Night & Day, 13.8 mm diameter), Menicon Z (8.8 mm diameter), and polymethylmethacrylate (8.8 mm diameter). Measurements were relativized to those recorded with no lens and with the polymethylmethacrylate lens. Friedman’s test was used to compare the mean relativized data across the contact lens materials. Post-hoc comparisons were performed using the methods described by Conover to control the overall alpha level for multiple comparisons.
There were significant differences (p=0.019) in the difference values between static and dynamic condition data across the seven lens materials/designs. The difference values, from highest to lowest, were associated with Ciba Night & Day, O2 Optics/14.0 diameter, O2 Optix/14.8 diameter, O2 Optix/13.2 diameter, Cooper Biofinity, Menicon Z, Acuvue Oasys.
Corneal oxygen demand differences among contact lens materials and designs are related to both corneal oxygen dynamics (lens transmissibility) and tear exchange (influenced by lens design and modulus).
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