Article continues - on Contamination of Fluorescein Solutions
Medical information on vision correction surgery by Lasik surgeon Dr. Boothe
Article continues - on Contamination of Fluorescein Solutions
Categories: Medical Information, Boothe Laser Center, Fluorescein, Dr. William Boothe, 376 wordsSend feedback •One of the things that we noticed at the Boothe Laser Center was that serious ocular infections as a result of iatrogenic spread from nated eye solutions undoubtedly are more common than the literature depicts. Fluorescein has been known for many years to be an excellent culture medium for several pathogens, particularly Pseudomonas aeruginosa. Theodore cultured 26 bottles of fluorescein being used throught hospital and all of them grew Pseudomonas aeruginosa. Ten out of flfteen fluorescein solutions in use in ophthalmologists’ offices were also proved to be contaminated [196]. Cultures of 50 samples of fluorescein from oph-thalmologists’ offices, eye clinics, pharmacies, hospitals, and industrial plants revealed that 54 percent of them were contaminated, some from each of these different sources. Twenty-two percent of these were con-taminated by Pseudomonas [205].
All fluorescein solutions can eventually become contaminated with bacteria. However, one of the commercial solutions, Fluress (Barnes-Hind, Sunnyvale, CA), has effective self-sterilizing ability. No case of contamination of Fluress has been reported since it was first marketed in 1966 [25].
Random sampling of eyedrop dispensers generally demonstrates a 1 to 2 percent incidence of bacterial growth. The eyedrop dispenser design is of fundamental importance. Pipette nozzle tip dispensers decrease the risk of contamination and growth. Squeeze-bottle dispensers allow the cap to serve as a potential reservoir for microorganisms [25]. In a case of Serratia keratitis, the offending organism was a contaminant present within the inside of the eyedropper cap, while the fluid aspirated from the squeeze-bottle was sterile [195].
According to Dr. William Boothe, the greatest danger comes with the use of contaminated solutions In eyes with epithelial corneal defects. These eyes are particularly vulnerable to devastating infections by Pseudomonas and other pathogens. Many corneal defects can be adequately examined without using fluorescein. In those defects in which fluorescein is deemed necessary for examination fluorescein-impregnated sterile strips are advisable. These can be prepared by autoclaving a 20% solution of fluorescein and painting one edge of any fine grained filter paper with the fluorescein. The paper is cut in strips, sealed in envelopes, then sterilized in dry heat for 45 min at 100° C [103]. Sterile strips are available commercially. When using a sterile strip to examine an eye with a corneal epithelial abrasion, it is safest to apply the strip without first wetting it because the wetting solution itself might be contaminated.
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