Advertisement

Exploring microwave irradiation as a method to disinfect contact lens cases

  • Brandon J. Goble
    Affiliations
    Agriculture and Medical Biotechnology, College of Agriculture, Food, and Environment, University of Kentucky, 506 Administration Drive, Lexington, KY 40506, United States

    Department of Mechanical Engineering, College of Engineering, University of Kentucky, 506 Administration Drive, Lexington, KY, 40506, United States
    Search for articles by this author
  • James D. Boyd
    Affiliations
    Department of Mechanical Engineering, College of Engineering, University of Kentucky, 506 Administration Drive, Lexington, KY, 40506, United States
    Search for articles by this author
  • Martha E. Grady
    Correspondence
    Corresponding author.
    Affiliations
    Department of Mechanical Engineering, College of Engineering, University of Kentucky, 506 Administration Drive, Lexington, KY, 40506, United States
    Search for articles by this author
Published:October 09, 2021DOI:https://doi.org/10.1016/j.clae.2021.101522

      Abstract

      Purpose

      Biofilm formation caused by infrequent contact lens case replacement and the ineffectiveness of multi-purpose solutions (MPS) on biofilm removal is associated with high rates of bacterial keratitis infections. This study demonstrated biofilm elimination from the contact lens case by microwave irradiation.

      Methods

      Staphylococcus aureus biofilms indicative of 3–9 months of contact wear were cultured in contact lens cases and visualized with crystal violet (CV) staining. Biofilms in contact cases were then exposed to four treatment regimens: No treatment (n = 8), 45 s microwave irradiation (n = 8), tap water (n = 6), and MPS (n = 9). Bacterial survival was assessed by colony forming unit (CFU) assay using streak dilutions.

      Results

      Visualization of the biofilms through CV staining revealed that biofilms coalesce between ribs of the contact case. In 5/8 cases no CFU were cultivated from the case after treatment with microwave irradiation. In tap water and MPS the first dilution averaged 6 ± 2 and 31 ± 13 CFUs per plate, respectively, while microwave irradiation averaged < 1 CFU per plate. In Dilution 2, the average reduced to 0.7 ± 0.7 and 6 ± 5 CFUs per plate for tap water and MPS, respectively, while microwave irradiation had 0 CFUs in Dilution 2.

      Conclusion

      Biofilms that coalesce between the ribs of the contact case pose a threat because this area is difficult to thoroughly scrub and could act as a basis for infection through fouling of contact lenses. Of the four treatment regimens, microwave irradiation displayed the most consistent and highest rate of bacterial eradication. Tap water was less effective compared to microwave irradiation, and poses other harmful side effects, but greatly reduced CFU count compared to no treatment. MPS displayed the poorest bacterial eradication of the treatments. Thus, microwave irradiation is worth further investigation as a viable in-home disinfecting option.

      Keywords

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'

      Subscribe:

      Subscribe to Contact Lens and Anterior Eye
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect

      References

        • Ibrahim Y.W.
        • Boase D.L.
        • Cree I.A.
        How could contact lens wearers be at risk of acanthamoeba infection?.
        A Review. J Optom. 2009; 2: 60-66
        • Collier S.A.
        Estimated Burden of Keratitis — United States, 2010.
        Morb Mortal Wkly Rep. 2014;
        • Obrubov A.S.
        • Slonimskii A.Y.
        Contact lens-related keratitis and purulent corneal ulcers.
        Vestn oftalmol. 2018; 134: 17-24
        • Bates A.K.
        • Morris R.J.
        • Stapleton F.
        • Minassian D.C.
        • Dart J.K.G.
        ‘Sterile’ corneal infiltrates in contact lens wearers.
        Eye. 1989; 3: 803-810
        • Hoffart L.
        • Dornadin A.
        • Drancourt M.
        Epidemiology of microbial keratitis: a review of 508 cases.
        Acta Ophthalmol. 2012; 90
        • Bui T.H.
        • Cavanagh H.D.
        • Robertson D.M.
        Patient compliance during contact lens wear: perceptions, awareness, and behavior.
        Eye & Contact Lens. 2010; 36: 334-339
        • Cope J.R.
        • Collier S.A.
        • Rao M.M.
        • Chalmers R.
        • Mitchell G.L.
        • Richdale K.
        • et al.
        Contact Lens Wearer Demographics and Risk Behaviors for Contact Lens-Related Eye Infections-United States, 2014.
        MMWR Morb Mortal Wkly Rep. 2015; 64: 865-870
        • Yung M.S.
        • Boost M.
        • Cho P.
        • Yap M.
        Microbial contamination of contact lenses and lens care accessories of soft contact lens wearers (university students) in Hong Kong.
        Ophthalmic Physiol Opt. 2007; 27: 11-21
        • Cho P.
        • Boost M.
        • Cheng R.
        Non-compliance and microbial contamination in orthokeratology.
        Optom Vis Sci. 2009; 86: 1227-1234
        • Hickson-Curran S.
        • Chalmers R.L.
        • Riley C.
        Patient attitudes and behavior regarding hygiene and replacement of soft contact lenses and storage cases.
        Cont Lens Anterior Eye. 2011; 34: 207-215
        • Wu Y.-Y.
        • Willcox M.
        • Zhu H.
        • Stapleton F.
        Contact lens hygiene compliance and lens case contamination: a review.
        Cont Lens Anterior Eye. 2015; 38: 307-316
        • Hall B.J.
        • Jones L.
        Contact lens cases: the missing link in contact lens safety?.
        Eye & Contact Lens. 2010; 36: 101-105
        • Wu Y.T.
        • Zhu H.
        • Harmis N.Y.
        • Iskandar S.Y.
        • Willcox M.
        • Stapleton F.
        Profile and frequency of microbial contamination of contact lens cases.
        Optom Vis Sci. 2010; 87: E152-E158
        • Mayo M.S.
        • Cook W.L.
        • Schlitzer R.L.
        • Ward M.A.
        • Wilson L.A.
        • Ahearn D.G.
        Antibiograms, serotypes, and plasmid profiles of Pseudomonas aeruginosa associated with corneal ulcers and contact lens wear.
        J Clin Microbiol. 1986; 24: 372-376
        • Cho P.
        • Boost M.V.
        Evaluation of prevention and disruption of biofilm in contact lens cases.
        Ophthalmic Physiol Opt. 2019; 39: 337-349
        • McLaughlin-Borlace L.
        • Stapleton F.
        • Matheson M.
        • Dart J.K.
        Bacterial biofilm on contact lenses and lens storage cases in wearers with microbial keratitis.
        J Appl Microbiol. 1998; 84: 827-838
        • Dart J.
        The inside story: why contact lens cases become contaminated.
        Cont Lens Anterior Eye. 1997; 20: 113-118
        • Costerton J.W.
        • Cheng K.J.
        • Geesey G.G.
        • Ladd T.I.
        • Nickel J.C.
        • Dasgupta M.
        • et al.
        Bacterial biofilms in nature and disease.
        Annu Rev Microbial. 1987; 41: 435-464
        • Gilbert P.
        • Das J.
        • Foley I.
        Biofilm susceptibility to antimicrobials.
        Adv Dent Res. 1997; 11: 160-167
        • Lewis K.
        Riddle of Biofilm Resistance.
        Antimicrob Agents Chemother. 2001; 45: 999-1007
        • Hildebrandt C.
        • Wagner D.
        • Kohlmann T.
        • Kramer A.
        In-vitro analysis of the microbicidal activity of 6 contact lens care solutions.
        BMC Infect Dis. 2012; 12: 241
        • Mohammadinia M.
        • Rahmani S.
        • Eslami G.
        • Ghassemi-Broumand M.
        • Aghazadh Amiri M.
        • Aghaie G.h.
        • et al.
        Contact lens disinfecting solutions antibacterial efficacy: comparison between clinical isolates and the standard ISO ATCC strains of Pseudomonas aeruginosa and Staphylococcus aureus.
        Eye. 2012; 26: 327-330
        • Wu Y.T.
        • Zhu H.
        • Willcox M.
        • Stapleton F.
        The effectiveness of various cleaning regimens and current guidelines in contact lens case biofilm removal.
        Invest Ophthalmol Vis Sci. 2011; 52: 5287-5292
        • Elias S.
        • Banin E.
        Multi-species biofilms: living with friendly neighbors.
        FEMS Microbiol Rev. 2012; 36: 990-1004
        • Devonshire P.
        • Munro F.A.
        • Abernethy C.
        • Clark B.J.
        Microbial contamination of contact lens cases in the west of Scotland.
        Br J Ophthalmol. 1993; 77: 41-45
        • Kaye R.
        • Kaye A.
        • Sueke H.
        • Neal T.
        • Winstanley C.
        • Horsburgh M.
        • et al.
        Recurrent bacterial keratitis.
        Invest Ophthalmol Vis Sci. 2013; 54: 4136https://doi.org/10.1167/iovs.13-12130
        • Siddiqui R.
        • Lakhundi S.
        • Khan N.A.
        Status of the effectiveness of contact lens solutions against keratitis-causing pathogens.
        Cont Lens Anterior Eye. 2015; 38: 34-38
        • Vijay A.K.
        • Willcox M.
        • Zhu H.
        • Stapleton F.
        Contact lens storage case hygiene practice and storage case contamination.
        Eye & Contact Lens. 2015; 41: 91-97
        • Hiti K.
        • Walochnik J.
        • Faschinger C.
        • Haller–Schober E.-M.
        • Aspöck H.
        Microwave treatment of contact lens cases contaminated with acanthamoeba.
        Cornea. 2001; 20: 467-470
        • Senna P.M.
        • Da Silva W.J.
        • Cury A.A.D.B.
        Denture disinfection by microwave energy: influence of Candida albicans biofilm.
        Gerodontology. 2012; 29: e186
        • Legarreta E.J.
        • Nau C.A.
        • Dhaliwal K.D.
        Acanthamoeba keratitis associated with tap water use during contact lens cleaning: manufacturer guidelines need to change.
        Eye Contact Lens: Sci Clin Practice. 2013; 39: 158-161
        • Hamida M.E.
        Effectiveness of ethanol and methanol alcohols on different isolates of staphylococcus species.
        J Bacteriol Mycol: Open Access. 2019; 7: 71-73
        • Wu Y.T.
        • Zhu H.
        • Willcox M.
        • Stapleton F.
        Removal of Biofilm from Contact Lens Storage Cases.
        Invest Ophthalmol Vis Sci. 2010; 51: 6329-6333
        • Woo I.-S.
        • Rhee I.-K.
        • Park H.-D.
        Differential damage in bacterial cells by microwave radiation on the basis of cell wall structure.
        Appl Environ Microbiol. 2000; 66: 2243-2247
      1. Annual Water Quality Report: Central Division Fayette and surrounding counties PWSID: KY0340250. Kentucky American Water. 2020.

        • Burnham G.W.
        • Cavanagh H.D.
        • Robertson D.M.
        The impact of cellular debris on Pseudomonas aeruginosa adherence to silicone hydrogel contact lenses and contact lens storage cases.
        Eye & Contact Lens. 2012; 38: 7-15
      2. Association AO. What You Need To Know About Contact Lens Care and Compliance.

        • Vadivambal R.
        • Jayas D.S.
        Non-uniform temperature distribution during microwave heating of food materials—a review.
        Food Bioprocess Technol. 2010; 3: 161-171
        • Luan D.
        • Wang Y.
        • Tang J.
        • Jain D.
        Frequency distribution in domestic microwave ovens and its influence on heating pattern.
        J Food Sci. 2017; 82: 429-436
        • Radford C.F.
        • Bacon A.S.
        • Dart J.K.G.
        • Minassian D.C.
        Risk factors for acanthamoeba keratitis in contact lens users: a case-control study.
        BMJ. 1995; 310: 1567-1570
      3. Contact Lens Branch DoOD, Office of Device Evaluation, Centers for Devices and Radiological Health. Premarket Notification (510(k)) Guidance Document for Daily Wear Contact Lenses. Food and Drug Administration, Department of Health and Human Services; 1994.