Contact lens storage case hygiene practice and storage case contamination

Area of Science:

• Ophthalmology
• Microbiology
• Biotechnology

Background:

• Persistent microbial contamination of contact lens storage cases is a significant risk factor for microbial keratitis.
• Current cleaning practices may not adequately remove robust microbial biofilms, posing a threat to ocular health.

Purpose of the Study:

• To evaluate the efficacy of various contact lens storage case cleaning techniques in removing microbial biofilms.
• To compare the effectiveness of different cleaning methods, including rinsing, air-drying, and tissue wiping, with and without disinfectants.

Main Methods:

• Contact lens storage cases were inoculated with Pseudomonas aeruginosa or Staphylococcus aureus biofilms.
• Cases were subjected to different cleaning protocols: rinsing with hot water or multipurpose solution (MPS), air-drying, and tissue wiping.
• The number of surviving microorganisms was quantified using standard culture techniques.

Main Results:

• Standard rinsing and air-drying were insufficient to remove significant amounts of S. aureus biofilms and only partially effective against P. aeruginosa biofilms.
• The most effective method for biofilm removal involved rinsing with MPS, followed by tissue wiping and air-drying.
• This combined approach significantly reduced microbial load for both P. aeruginosa and S. aureus.

Conclusions:

• Staphylococcus aureus biofilms, though less dense, were more resistant to cleaning procedures than Pseudomonas aeruginosa biofilms.
• Simple rinsing and air-drying are inadequate for eliminating heavy microbial biofilms from contact lens cases.
• A comprehensive cleaning regimen including MPS rinsing, tissue wiping, and air-drying is recommended for optimal contact lens case hygiene.