Peroxid ebenfalls keine Wunderwaffe
Donnerstag, 12. Juli 2007Neue Studien von Dr. Gary Andrasko und Dr. Kelly Ryen nachzulesen auf Staininggrid.com ergaben, dass Peroxid wohl doch keine Wunderwaffe für Akantamöben ist.
Um diese abzutöten müssten die Kontaktlinsen über 4 Stunden in Peroxid liegen bevor die Neutralisation beginnt. Bei den Tabletten – Peroxidsystemen wird die Tablette normalerweise direkt mit in die Flüssigkeit gelegt.
Bei Systemen mit Katalysator hat man überhaupt keinen Einfluss, da die Flüssigkeit direkt beim einfüllen in den Behälter, beginnt zu neutralisieren.
Aus den Texten geht wieder einmal hervor wie wichtig der richtige Umgang mit den Linsen ist. Gründliches Händewaschen vor dem Auf- und Absetzen der Kontaktlinsen, eine manuelle Reinigung der Kontaktlinsen und regelmäßige Kontrollen minimieren das Risiko erheblich.
Fürs Schwimmen oder ähnliche Tätigkeiten in Gewässern sollte also auf Tageslinsen zurückgegriffen werden. Hier ist keinerlei Pflegemittel von nöten.
Is No Rub really a good idea?
No Rub method of lens care was an interesting experiment. Results of several studies indicate that rubbing and rinsing the contact lens before storage effectively removes several log units of microorganisms from the lens surface. The remaining bugs are then effectively killed by the disinfecting solution. Based upon what we know today Rub and Rinse should undoubtedly be the standard.
Should all patients be switched to a hydrogen peroxide-based disinfection system?
Hydrogen peroxide is effective against acanthamoeba if the disinfecting solution is at full strength for a 4-hour soak. Current one-step systems begin to neutralize immediately upon contact with the disk. A two-step system where the patient delays inserting a neutralizing tablet for at least 4 hours would be ideal but probably not practical based upon the history of dubious patient compliance.
What can practitioners do to protect their patients from all types of microbial keratitis?
In short there are no procedures or lens care regimens which offer 100% assurance that a patient won’t suffer a microbial infection. As with all aspects of medicine we are limited to minimizing the risk factors, both known and suspected. Review and emphasize with patients the necessity of strict adherence to all cleaning and disinfecting instructions. Also review the importance of hand washing, sticking to the prescribed wearing schedule (i.e., daily wear, flexible wear, etc.) and other known risk factors such as smoking and ocular exposure to contaminated water supplies. Finally, carefully examine contact lens wearers for corneal staining, infiltrates, chronic hyperemia, and tear film deficiencies.







