Purpose: To evaluate the efficacy of a novel daily disposable (DD) flat package in regard to microbial contamination on the anterior and posterior surfaces of a contact lens (CL) during handling of the lens for insertion.
Methods: Four kinds of commercially available general blister-packed daily disposable contact lenses (DD CLs) as controls and a novel Magic 1-day Menicon Flat Pack as a test lens were used for this in vitro study. Lenses were removed from their packages using fingers coated with fluorescein 3 to 5 μm beads or an approximately 7×102 to 2×103 colony-forming unit (CFU)/mL Staphylococcus aureus suspension. The transfer of fluorescein beads to the surface of the lenses was then observed by fluorescence microscopy. Microbial contamination on the lenses was observed by light microscopy after a 2-day incubation period; and, the number of colonies isolated from the contaminated lenses was determined after 4 days of incubation.
Results: The number of fluorescein beads on the Magic lens was significantly less (p<0.05) than that of the general blister-packed control lenses. Adherence of microbial colonies was observed on both inner and outer surfaces of general blister-packed lenses, whereas no colony formation was found on the inner surface of the Magic lens, and the lowest bacterial adherence was observed for the Magic lens.
Conclusions: The data demonstrated that placement of the Magic DD lens onto the eye is accompanied by diminished microbial contamination compared with general blister-packed DD CLs. Eye care professionals; however, should instruct patients to comply with intended use of DD CLs to prevent CL-associated microbial keratitis. In all cases, hand washing is mandated prelens insertion.
Research & Development (M.N., K.S., H.I.), Menicon Co., Ltd., Aoi, Naka-ku, Nagoya, Aichi, Japan; and Department of Ophthalmology (H.D.C.), University of Texas, Southwestern Medical Center at Dallas, Dallas, TX.
The authors M.N., K.S., and H.I. are employees of and H.D.C. is a consultant for Menicon Co., Ltd., Nagoya, Japan.
Address correspondence and reprint requests to Hideji Ichijima, M.S., Menicon Co., Ltd. 3-21-19, Aoi, Naka-ku, Nagoya 460-0006, Aichi, Japan; e-mail: firstname.lastname@example.org
Accepted February 6, 2013