Adhesion ofAcanthamoebaon Cosmetic Contact Lenses

Abstract

BackgroundThis study aimed to evaluate the adhesion of Acanthamoeba trophozoites on cosmetic contact lenses (CLs) with and without CL care multipurpose solution (MPS) treatment.MethodsAcanthamoeba lugdunensis L3a trophozoites were inoculated onto disks trimmed from CLs: 1-day Acuvue moist, 1-day Acuvue define, Acuvue 2, and Acuvue 2 define. After 18-hour inoculation, the number of adherent trophozoites was counted under phase contrast microscopy. The effects of MPS, Opti-Free Express, soaking CLs for 6 hours, on Acanthamoeba adhesion were analyzed. Scanning electron microscopic examination was performed for assessment of Acanthamoeba attached on the lens surface.ResultsAcanthamoeba trophozoites showed greater adhesion to cosmetic CL (P = 0.017 for 1-day CL and P = 0.009 for 2-week CL) although there was no significant difference between the types of cosmetic CL. On all lenses, the number of adherent Acanthamoeba was significantly reduced after treatment with MPS (P < 0.001 for 1-day Acuvue moist, P = 0.046 for 1-day Acuvue define, P < 0.001 for Acuvue 2, and P = 0.015 for Acuvue 2 define), but there was still significant difference between conventional and cosmetic CLs (P = 0.003 for 1-day CL and P < 0.001 for 2-week CL, respectively). More attachment of Acanthamoeba was observed on colored area and the acanthopodia of Acanthamoeba was placed on the rough surface of colored area.ConclusionAcanthamoeba showed a greater affinity for cosmetic CL and mostly attached on colored area. Although MPS that contained myristamidopropyl dimethylamine reduced the adhesion rate, there was a significant difference between conventional and cosmetic CLs.

Acanthamoeba keratitis: a review of biology, pathophysiology and epidemiology

“…74 Cosmetic soft lenses are often associated with a lack of maintenance and poor hygiene habits, as these lenses may be bought without a prescription and proper education, and therefore represent increased risk for AK. 56,154…”

“…21 MPS are recommended in about 90% of disinfection systems prescribed for soft CLs. 160 Soft CL MPS typically consist of several components, such as an aqueous liquid medium, antimicrobial and preservative, surfactant, chelating, wetting, buffering, 39 tonicity and viscosity-inducing elements 72,107,154 conferring stability and efficacy in the disinfection process. 39 These solutions are used to clean CLs and cases through wiping, rinsing and rubbing procedures, which cause the displacement of cysts and trophozoites and decreases the associated bacterial count.…”

“…These lenses are generally used overnight 19 and cause modification of the central cornea with reverse geometry producing corneal flattening, 19,79 but hypoxia may develop during wearing hours 74 . Cosmetic soft lenses are often associated with a lack of maintenance and poor hygiene habits, as these lenses may be bought without a prescription and proper education, and therefore represent increased risk for AK 56,154 …”

“…Myristamidopropyl dimethylamine (MAPD): present in MP. It causes a decrease in adhesion of organisms to cosmetic and conventional lenses 154 Polyquaternium‐1: disinfection base that does not act on Acanthamoeba and fungi, but is effective in bacteria such as Staphylococcus aureus , Pseudomonas aeruginosa and Serratia marcescens 35 .…”

Assessment of ocular surface response to tinted soft contact lenses with different characteristics and pigment location

“…[9] Other studies have also reported that bacteria have greater affinity for tinted surfaces than for uncolored or convex areas. [10,11] The presence of pigment on the surface of the lens may make it uneven, making it thicker and less smooth than a conventional contact lens, probably with lower oxygen permeability. Many articles have reported that direct contact between a pigment layer on the surface of tinted soft contact lenses and human tissue can lead to eye irritation or even serious complications.…”