Abstract | PURPOSE: To investigate whether optimized photoactivated chromophore for keratitis- corneal collagen cross-linking (PACK-CXL) treatment settings allow accelerating treatment while maintaining antibacterial efficacy. METHODS: Staphylococcus aureus and Pseudomonas aeruginosa strains were irradiated with ultraviolet-A light of equal fluence but different intensity settings (18 mW/cm² for 5 minutes and 36 mW/cm² for 2.5 minutes). The killing rate was determined by comparing the number of colony-forming units between cross-linked specimens and non-irradiated controls. The potential additional effect of 0.001% benzalkonium chloride was also investigated. RESULTS: The killing rates for Staphylococcus aureus were 92.5% ± 5.5% (5 minutes at 18 mW/cm²) and 94.4% ± 2.9% (2.5 minutes at 36 mW/cm²). For Pseudomonas aeruginosa, the killing rates were 93.2% ± 8.3% (5 minutes at 18 mW/cm²) and 92.9% ± 5.0% (2.5 minutes at 36 mW/cm²). The presence of benzalkonium chloride in the riboflavin solution did not increase the killing rate significantly. CONCLUSIONS: The antibacterial efficacy of PACK-CXL follows the Bunsen-Roscoe law of reciprocity and can be maintained even when the irradiation intensity is considerably increased. These optimized settings may allow a shortened treatment time in the future for PACK-CXL and thus help facilitate the transition from the operating room to the slit lamp for treatment.
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Authors | Olivier Richoz, Sabine Kling, Florence Hoogewoud, Arthur Hammer, David Tabibian, Patrice Francois, Jacques Schrenzel, Farhad Hafezi |
Journal | Journal of refractive surgery (Thorofare, N.J. : 1995)
(J Refract Surg)
Vol. 30
Issue 12
Pg. 850-4
(Dec 2014)
ISSN: 1081-597X [Print] United States |
PMID | 25437485
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | Copyright 2014, SLACK Incorporated. |
Chemical References |
- Anti-Bacterial Agents
- Benzalkonium Compounds
- Photosensitizing Agents
- Riboflavin
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Topics |
- Animals
- Anti-Bacterial Agents
(pharmacology, therapeutic use)
- Benzalkonium Compounds
(pharmacology)
- Colony Count, Microbial
- Corneal Ulcer
(drug therapy, microbiology)
- Eye Infections, Bacterial
(drug therapy, microbiology)
- Photosensitizing Agents
(therapeutic use)
- Pseudomonas Infections
(drug therapy, microbiology)
- Pseudomonas aeruginosa
(drug effects, isolation & purification, radiation effects)
- Riboflavin
(pharmacology, therapeutic use)
- Staphylococcal Infections
(drug therapy, microbiology)
- Staphylococcus aureus
(drug effects, isolation & purification, radiation effects)
- Swine
- Ultraviolet Rays
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