Aims to determine if plasma surface treatment of Focus Night & Day silicone hydrogel contact lenses affects the attachment of Acanthamoeba. Unworn lotrafilcon A contact lenses with (Focus Night & Day) and with out surface treatment and Acuvue, conventional hydrogel lenses were quartered prior to 90 minutes incubation with Acanthamoeba castellanii trophozoites. After incubation and rinsing the trophozoites attached to one surface of each quarter were counted by direct light microscopy. Sixteen replicates were observed for each lens type. Logarithmic transformation of data allowed the use of parametric ANOVA. No significant difference in attachment was established between the untreated lotrafilcon A lens and the conventional hydrogel (p<0.001), however surface treatment of the native Focus Night & Day material produced a significant increase in attachment (p<0.001). Commercially available Focus Night & Day lenses are subjected to a plasma surface treatment to reduce lens hydrophobicity, however this procedure results in enhanced Acanthamoebal attachment. It is possible that the silicone hydrogel lens could be at greater risk of be promoting Acanthamoeba infection if exposed to the organism, due to the enhanced attachment characteristic of this material. Eye care professionals should be aware of the enhanced affinity Acanthamoeba show for this lens, and accordingly emphasise to patients the significance of appropriate lens hygiene. This is particularly important where lenses are worn in a regime which could increase the chance of exposure to the organism, i.e. 6 night/7 day extended wear or daily wear where lenses will be stored in a lens case, or where lenses are worn when in contact with potentially contaminated water sources, i.e. swimming or shower.
- contact lenses
- eye infection