Microbial contamination of hydrophilic contact lenses. Part II: Quantitation of microbes after patient handling and after aseptic removal from the eye.
We cultured Soflens (polymacon) contact lenses to determine the number of microorganisms present after patient handling and the number present after patient handling and 5 hours of lens wear. Twenty adapted contact lens patients were each dispensed two pairs of new sterile Soflens contact lenses. Both pairs of lenses were handled by the patients during a single experimental session. Prior to handling lenses, patients were instructed to wash their hands with soap and water, rinse with tap water, and dry with a paper towel. One pair (handled-only) was cultured immediately after handling. The second pair (handled-and-worn) was placed on the eyes by the patient, removed aseptically following 5 hours of wear, and then cultured. All 40 handled-only lenses had viable microorganisms associated with them (mean: 653 colony forming units (CFU) per lens). Bacteria were isolated on all of these lenses and fungi were detected on six. The mean bacterial count for the handled-and-worn lenses was 30 CFU/lens; fewer than half exhibited handled-and-worn lenses was 30 CFU/lens; fewer than half exhibited bacteria and no fungi were isolated. These data suggest that patient handling is a highly significant source of microbial contamination of hydrophilic contact lenses. Also, the number of microorganisms on lenses is significantly reduced (P < 0.0001) after the lens has been worn on the eye.
Mowrey-McKee
M F
MF
Personal Products Division, Bausch & Lomb, Rochester, NY.
Sampson
H J
HJ
Proskin
H M
HM
D001207:Asepsis; D001419:Bacteria / Q000302:isolation & purification*; D015169:Colony Count, Microbial; D003263:Contact Lenses, Hydrophilic; D004203:Disinfection; D004866:Equipment Contamination; D005658:Fungi / Q000302:isolation & purification*; D006235:Hand Disinfection; D006801:Humans; D010349:Patient Compliance; D013048:Specimen Handling