Microbial adherence to cosmetic contact lenses.
OBJECTIVE
To investigate whether cosmetic contact lenses (CCL) with surface pigments affect microbial adherence.


METHODS
Fifteen brands of CCL were purchased from optical, non-optical retail outlets, and via the Internet. A standardized rub-off test was performed on each CCL (five lenses per brand) to confirm the location of the pigments. The rub-off test comprised gentle rubbing on the surfaces of each CCL with wetted cotton buds for a maximum of 20 rubs per surface. A new set of CCL (five lenses per brand) were incubated in Pseudomonas aeruginosa overnight. Viable counts of adhered bacteria were determined by the number of colony-forming units (CFU) on agar media on each lens. The adherence of P. aeruginosa as well as Staphylococcus aureus and Serratia marcescens to three brands of CCL (A-C) (five lenses per brand) were also compared to their adherences on their clear counterparts.


RESULTS
Only two of the 15 brands of CCL tested (brands B and C) had pigments that did not detach with the rub-off test. The remaining 13 brands of CCL all failed the rub-off test and these lenses showed higher P. aeruginosa adherence (8.7 × 10(5)-1.9 × 10(6) CFU/lens). Brands B and C lenses showed at least six times less bacterial adhesion than the other 13 brands. Compared to their clear counterparts, bacterial adherence to brands B and C lenses did not differ significantly, whereas brand A lenses showed significantly higher adherence.


CONCLUSIONS
Surface pigments on CCL resulted in significantly higher bacterial adherence.
School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region. Electronic address: kayin.chan@connect.polyu.hk.
Ka Yin
KY
Chan
School of Optometry, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region.
Pauline
P
Cho
Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Hong Kong Special Administrative Region.
Maureen
M
Boost
D000327:Adsorption; D001422:Bacterial Adhesion / Q000187:drug effects*; D004396:Coloring Agents / Q000032:analysis / Q000737:chemistry*; D018639:Contact Lens Solutions / Q000737:chemistry / Q000494:pharmacology*; D003261:Contact Lenses / Q000382:microbiology*; D003357:Cosmetic Techniques / Q000295:instrumentation*; D004203:Disinfection / Q000379:methods*; D004866:Equipment Contamination / Q000517:prevention & control; D004867:Equipment Design; D019544:Equipment Failure Analysis; D013499:Surface Properties
D004396:Coloring Agents; D018639:Contact Lens Solutions
Bacterial adherence; Coloured contact lenses; Cosmetic contact lenses; Decorative contact lenses; Microbial adherence