Ophthalmology & Optometry/Tonometer/Glaucoma testing
QUESTION: I have been reading that because the tip of the tonometer touches the cornea diseases can be transmitted. The doctors offices when testing for Glaucoma only use an alcohol pad to clean the applicator. The CDC recommends soaking in bleach and rinsing with water which is not done because it is too time consuming. What is a patient to do to protect themselves? I want to get tested but am very worried.
ANSWER: Hi Joy,
there are disposable tonotips available, but I have read that alcohol is fine and effective, and prefer it. The non contact air puff tonometer is also acceptable. You are more likely to get sick being in any public place, and ask if the chin and forehead rests are sanitized before placing your head in the instruments.
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QUESTION: Thank you for your reply.
I did try, but have not been able to find providers that use the disposable tonotips because I am told they are too expensive to use and throw away on every patient.
I am wondering if the disposable tonotips are available and generic to fit all the Goldman machines?
Please understand I am not at all concerned with the chin or forehead rests as I have my skin to protect me. Public places do not touch the insides or private parts of my body.
The Society for Micro biology and the Association for Professional Infection Control says simply wiping the tonometer with 70% isopropyl alcohol is not effective for all pathogens. They say the only thing it has been found effective for on the tonometer is HIV and that is because it is a very fragile virus. Studies I could find say it is not effective for any kinds of the adenoviruses at all. That also leaves questions about other pathogens such as hepatitis? One article addressed transmission of CJD an infectious dementia and conjunctiva associated lymphatic tissues.
If you contracted hepatitis or other diseases that take time to show symptoms the source could not be traced because there would be no controls.
Please let me know where I can find a professional article or study that says wiping with an alcohol pad is fine and effective. The CDC and info I could find on the internet is causes reason for concern. This would relieve my mind. Thank you so much.
I guess it depends on the technique as well as the agent.
I'm not sure why you're assuming wipe vs soak, it seems a thorough wipe could be considered. .
Mitch Axelrod, OD
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QUESTION: With much thanks for your reply.
I was unable to access the 1st article. At the sight there was a phone number but it was not in the USA. I found the second article from the Indian Journal of Ophthalmology (1998) Hydrabad, India but I found the information was based on references to outdated findings.
I do though see what you are saying when you conclude that it depends on technique as well as agent. From my readings it does indicate that there needs to be correct exposure times for chosen disinfectants.
The National Institute of Health from research done by the Washington University School of Medicine found that with 70% alcohol wipes 88.91% of Hepatitis virus remained. With just a cold water wash only 4.78% remained and with an alcohol soak followed by cold water rinse only a very tiny 0.02% of virus remained. Sounds like the cold water rinse is what eliminates a good portion of virus on the tonometer.
The manufacturer instructions for use recommends a bleach solution soak for 10 minutes and through rinse.
I am assuming wipe vs soak because the soaks all call for a rinse. It would seem reasonable that a thorough wipe could be considered but would need to be followed by a rinse. The rinse part seems to be extremely important in washing away pathogens, even more so than the 5 or 10 minute soak.
One article I came across said that washing with soap and water would eliminate a good percentage of viral matter from the tonometer tip.
The information would conclude with the Center for Disease Control advice that alcohol wipes (70%) are not effective and should not be used.
Also with the most recent research data from the National Institute of Health and the manufacturer recommendations. All include a rinsing.
All US or European research studies I came across point to soaking in alcohol or peroxide and then rinsing with clear fresh tap water or the use of disposables for patient safety.
I would feel safe with an alcohol wipe instead of soak which would save time if it included a rinse but I am coming to the conclusion that the rinse part is the most important in eliminating pathogens from the tonometer.
I would greatly appreciate your professional opinion and response to my conclusions. Thank you so very much.
Hi Joy, You have a good handle on the issue, following this is from the link that didn't work for you. I think this should end our dialogue, just speak to your eye doctor about your concern and ask them to disinfect in front of you.
American Journal of Ophthalmology
Volume 131, Issue 2 , Pages 184-187, February 2001
Disinfection of Goldmann tonometers after contamination with hepatitis C virus☆
William A Segal, MD
, Jonathan R Pirnazar, MD
, Max Arens, PhD
, Jay S Pepose, MD, PhD
Corresponding Author Information
Accepted 24 August 2000.
PURPOSE: To compare methods of disinfecting Goldmann tonometer tips inoculated with hepatitis C virus.
METHODS: Hepatitis C virus was placed on Goldmann tonometer tips, air dried, and then disinfected by dry gauze wipes, isopropyl alcohol wipes, cold water washes, povidone iodine 10% wipes, and hydrogen peroxide or isopropyl alcohol soaks followed by a cold water wash and dry. Hydrogen peroxide and isopropyl alcohol disinfection techniques followed the Centers for Disease Control and Prevention guidelines for prevention of possible transmission of human immunodeficiency virus (HIV). After disinfection, samples from tonometer tips were amplified by polymerase chain reaction to quantitate the amount of hepatitis C virus RNA remaining.
RESULTS: Percentage of hepatitis C virus RNA remaining after disinfection: dry gauze wipes 95.65%, isopropyl alcohol 5-second wipes 88.91%, cold water wash 4.78%, povidone iodine 10% 5-second wipes 0.72%, hydrogen peroxide soak with cold water wash 0.07%, and isopropyl alcohol soak and cold water wash 0.02%.
CONCLUSIONS: After inoculation of Goldmann tonometer tips with hepatitis C virus, a 5-minute soak in 3% hydrogen peroxide or 70% isopropyl alcohol followed by washing in cold water resulted in the greatest reduction in hepatitis C virus RNA.