Antimicrobial blue light therapy for infectious keratitis: Ex vivo and in vivo studies

Hong Zhu, Irene E. Kochevar, Irmgard Behlau, Jie Zhao, Fenghua Wang, Yucheng Wang, Xiaodong Sun, Michael R. Hamblin, Tianhong Dai

Research output: Contribution to journalArticlepeer-review

25 Citations (Scopus)


PURPOSE. To investigate the effectiveness of antimicrobial blue light (aBL) as an alternative or adjunctive therapeutic for infectious keratitis. METHODS. We developed an ex vivo rabbit model and an in vivo mouse model of infectious keratitis. A bioluminescent strain of Pseudomonas aeruginosa was used as the causative pathogen, allowing noninvasive monitoring of the extent of infection in real time via bioluminescence imaging. Quantitation of bacterial luminescence was correlated to colonyforming units (CFU). Using the ex vivo and in vivo models, the effectiveness of aBL (415 nm) for the treatment of keratitis was evaluated as a function of radiant exposure when aBL was delivered at 6 or 24 hours after bacterial inoculation. The aBL exposures calculated to reach the retina were compared to the American National Standards Institute standards to estimate aBL retinal safety. RESULTS. Pseudomonas aeruginosa keratitis fully developed in both the ex vivo and in vivo models at 24 hours post inoculation. Bacterial luminescence in the infected corneas correlated linearly to CFU (R2 = 0.921). Bacterial burden in the infected corneas was rapidly and significantly reduced (>2-log10) both ex vivo and in vivo after a single exposure of aBL. Recurrence of infection was observed in the aBL-treated mice at 24 hours after aBL exposure. The aBL toxicity to the retina is largely dependent on the aBL transmission of the cornea. CONCLUSIONS. Antimicrobial blue light is a potential alternative or adjunctive therapeutic for infectious keratitis. Further studies of corneal and retinal safety using large animal models, in which the ocular anatomies are similar to that of humans, are warranted.

Original languageEnglish
Pages (from-to)586-593
Number of pages8
JournalInvestigative Ophthalmology and Visual Science
Issue number1
Publication statusPublished - 1 Jan 2017
Externally publishedYes


  • Antimicrobial blue light
  • Bioluminescence imaging
  • Keratitis
  • Mouse model
  • Pseudomonas aeruginosa
  • Rabbit model

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience


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