Purchase this article with an account.
Heather Sheardown, Lina Liu; Wetting Agent Release from Astigmatic Lenses. Invest. Ophthalmol. Vis. Sci. 2011;52(14):6532.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
1-Day Acuvue® for Astigmatism contact lenses (J&J Vision Care, USA) (AA) and Focus Dailies for Astigmatism (CIBA Vision) (FA) are one day disposable conventional hydrogel lenses designed for astigmatic patients. Release of the wetting agents poly vinyl alcohol (PVA) and poly vinyl pyrollidone (PVP) from these two lens materials was examined to assess whether any embedded wetting agent remains in the lens or is released into the surrounding ocular environment.
Lenses were removed from their packaging solutions and placed in PBS at 35oC. Releasate was collected at regular intervals and dialyzed to remove low molecular weight impurities. The release solutions were analyzed for PVP using a variety of methods, including UV spectrophotometry, gel permeation chromatography, FTIR, HPLC and mass spectroscopy to assess whether the wetting agent was released and to quantify any such release. As well, release solutions were analyzed for PVA using a published iodine based assay. Analyses of the packing solutions were also performed for comparison.
All analytical results for the releasates demonstrate that the embedded PVP wetting agent is not released in measurable quantities from any lens at any time during a simulated wear period of 15 hours. Small HPLC peaks were observed from all three lens types. The iodine assay suggested that in the case of the FA lenses, these peaks can likely be attributed to the released PVA wetting agent. These results suggest that approximately 1.2 mg of PVA are released per lens and that much of this release occurs during the initial two hours of incubation. No PVA was observed in the AA releaseates.
AA lenses contain an internal wetting agent that is not released in measurable quantities in PBS over a simulated wear period of 15 hours. PVA release was observed, particularly in the first two hours, from the FA lenses.
This PDF is available to Subscribers Only