Attachment of Acanthamoeba to First- and Second-Generation Silicone Hydrogel Contact Lenses

Temporal and Seasonal Trends in Acanthamoeba Keratitis

“…Although silicone hydrogel contact lenses demonstrate high oxygen permeability (Dk), which significantly reduces corneal hypoxia compared with traditional hydrogel lenses, 23 their extended continuous wear for more than 30 days and the increased Acanthamoeba species adhesion to the firstgeneration silicone hydrogel lenses, compared with traditional hydrogels, may increase the risk of keratitis caused by this organism. 24,25 We also postulate that improvements in the design and comfort of newer contact lenses and the easy availability of contact lenses over the Internet, without supervision by an eye care professional, have led to the perceived safety of newer contact lenses, by both patients and contact lens practitioners, and a subsequent complacency with regard to lens hygiene and wear time.…”

Diagnosis and management of Acanthamoeba keratitis

“…While this study did not have any cases of Acanthamoeba infection, continuous-wear regimens obviate contact lens handling, cases and solutions. Thus, if these lenses are used, it is recommended that they be used in a continuous-wear fashion [19]. More recently, the same group studied the so-called second generation of silicone hydrogel lenses, Acuvue Advance (Johnson & Johnson Vision Care, New Jacksonville, Florida, USA), composed of galyfilcon A 19 .…”

Microbial Keratitis and the Role of Rub and Rinsing

“…This increased attachment was thought to be an inherent characteristic of the polymer itself or a side effect of the surface modification procedure that occurs during lens manufacture. 15 More recent work 16 compared Acanthamoeba attachment to original, first-generation silicone hydrogel materials and newer, second-generation materials, including consideration of the influence of biofilm and patient wear. Results showed a significantly higher attachment for first-generation silicone hydrogel materials than for second-generation silicone hydrogel lenses or conventional polyhydroxyethylmethacrylate-based hydrogel lenses.…”