June 2023
Volume 64, Issue 8
Open Access
ARVO Annual Meeting Abstract  |   June 2023
Methylene Blue Photodynamic Antimicrobial Therapy Inhibition Against Common Ocular Isolates In Vitro
Author Affiliations & Notes
  • Brandon Chou
    Ophthalmic Biophysics Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
  • Katherine Krishna
    Ophthalmic Biophysics Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
  • Heather Ann Durkee
    Ophthalmic Biophysics Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
  • Felipe Echeverri
    Ophthalmic Biophysics Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
  • James Lai
    Ophthalmic Biophysics Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
  • Guillermo Amescua
    Anne Bates Leach Eye Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
    Ophthalmic Biophysics Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
  • Darlene Miller
    Ocular Microbiology Laboratory, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
    Anne Bates Leach Eye Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
  • Jean-Marie Parel
    Ophthalmic Biophysics Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
    Anne Bates Leach Eye Center, Department of Ophthalmology, University of Miami Health System Bascom Palmer Eye Institute, Miami, Florida, United States
  • Footnotes
    Commercial Relationships   Brandon Chou None; Katherine Krishna None; Heather Durkee University of Miami, Code P (Patent); Felipe Echeverri None; James Lai None; Guillermo Amescua University of Miami, Code P (Patent); Darlene Miller University of Miami, Code P (Patent); Jean-Marie Parel University of Miami, Code P (Patent)
  • Footnotes
    Support  This work was financially supported in part by the Florida Lions Eye Bank and the Beauty of Sight Foundation, the Edward D. and Janet K. Robson Foundation, NIH Center Grant (P30EY14801), Research to Prevent Blindness – Unrestricted Grant to BPEI (GR004596), the Henri and Flore Lesieur Foundation (JMP), and donations from Drs. Harry W. Flynn Jr, Karl R. Olsen, Martha E. Hildebrandt, Raksha Urs, Aaron Furtado.
Investigative Ophthalmology & Visual Science June 2023, Vol.64, 608. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Brandon Chou, Katherine Krishna, Heather Ann Durkee, Felipe Echeverri, James Lai, Guillermo Amescua, Darlene Miller, Jean-Marie Parel; Methylene Blue Photodynamic Antimicrobial Therapy Inhibition Against Common Ocular Isolates In Vitro. Invest. Ophthalmol. Vis. Sci. 2023;64(8):608.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose : Infectious keratitis is the leading cause of corneal blindness and pose a treatment challenge to physicians. One novel approach is rose bengal photodynamic antimicrobial therapy, but this treatment is still limited by the superficial penetration of the rose bengal into the cornea. PDAT with methylene blue (MB) has been used in oral applications with positive outcomes against biofilm and could provide better outcomes in keratitis. This study will evaluate the use of photodynamic antimicrobial therapy with methylene blue to inhibit the growth of the most common ocular infectious isolates in vitro.

Methods : Seven bacteria isolates (Pseudomonas aeruginosa, (n=5), methicillin-susceptible Staphylococcus aureus (MSSA), (n=1), and methicillin-resistant Staphylococcus aureus (MRSA), (n=1)) and ten fungal isolates (Candida albicans, (n=2), Fusarium spp., (n=3), and Aspergillus spp., (n=5)) were isolated from patients with ocular infections and grown on agar plates. Testing organism concentration was prepared to 1x10E4 for all organisms. Test plates were separated into three groups for each organism: (1) control (isolate only), (2) 0.1% methylene blue without irradiation, (3) 0.1% methylene blue with irradiation. An off-the-shelf 10 mW, 660nm LED light array was used to irradiate the plates for 15 minutes (energy density 9 J/cm2). Plates were incubated at 30°C for 48 to 72 hours and then photographs were taken to document the organism growth by quantifying the number of surviving colonies in a central 50mm zone.

Results : Methylene blue with red light fully inhibited both the MRSA and MSSA strains but had no effect on pseudomonas aeruginosa. For the fungal isolates, all conditions (MB with and without red light) had no effect after 72 hours of incubation.

Conclusions : MB PDAT inhibited MRSA and MSSA in the irradiation zones and did not inhibit any fungal or pseudomonas aeruginosa growth. We did not find that the current concentration of MB and amount of irradiation were effective and should be varied in future studies to find optimal parameters for inhibiting ocular isolate growth. However, MB PDAT could be examined as an alternative treatment for bacterial ocular pathogens and potential biofilm inhibition for ocular isolates.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.

 

Figure 1 Growth inhibition results from MB PDAT. (Top) Control plates (Middle) MB without irradiation (Bottom) MB with irradiation.

Figure 1 Growth inhibition results from MB PDAT. (Top) Control plates (Middle) MB without irradiation (Bottom) MB with irradiation.

×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×