Antimicrobial Efficacy of an Ultraviolet-C Device against Microorganisms Related to Contact Lens Adverse Events

Srikanth Dumpati, Shehzad A. Naroo, Sunil Shah, Debarun Dutta*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


The purpose of the study was to assess the antimicrobial activity of an ultraviolet-C (UVC) device against microorganisms implicated in contact lens related adverse events. An UVC device with an emitting 4.5 mm diameter Light Emitting Diode (LED; 265 nm; 1.93 mJ/cm2) was used. Pseudomonas aeruginosa, Staphylococcus aureus, Fusarium solani, and Candida albicans agar plate lawns were exposed to the device beams for 15 and 30 s at 8 mm distance. Following the exposure, the diameter of the growth inhibition zone was recorded. Contact lenses made of Delfilicon-A, Senofilicon-A, Comfilicon-A, Balafilicon-A, Samfilicon-A and Omafilicon-A and a commercially available contact storage case was used. They were exposed to bacterial and fungal strains for 18 h at 37 °C and 25 °C respectively. After this, the samples were exposed to UVC for 30 s at 8 mm distance to determine the antimicrobial efficacy. Samples were then gently washed and plated on appropriate agar for enumeration of colonies. The UVC exposure reduced microbial growth by 100% in agar lawns, and significantly (p 0.05) reduced microbial contamination to contact lenses and cases, ranging between 0.90 to 4.6 log. Very short UVC exposure has high antimicrobial efficacy against most of the predominant causative microorganisms implicated in contact lens related keratitis. UVC could be readily used as a broad-spectrum antimicrobial treatment for lens disinfection.
Original languageEnglish
Article number699
Issue number5
Publication statusPublished - 21 May 2022

Bibliographical note

© 2022 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
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Funding: This research was funded by Marie Skłodowska-Curie COFUND Programme of European Union, grant number 713694 and by Photon Therapeutics Ltd.


  • contact lenses
  • ultraviolet C
  • keratitis
  • Pseudomonas
  • Staphylococcus
  • Fusarium
  • Candida
  • antibiotic resistance


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