New Case for Your Biofinity Contacts

HelpMeRhonda · #1 (**permalink**) 09-29-2008, 08:58 AM

How often do you replace the case that you store your Frequency 38 contacts in? I heard a suggestion that you should change the case every time you buy a new bottle of solution.

porcelina68 · #2 (**permalink**) 04-15-2009, 03:44 PM

The recommended time frame to change your lens case for any brand of contact lens is 3 months.

HelpMeRhonda · #3 (**permalink**) 05-21-2009, 08:32 AM

Quote:

Originally Posted by porcelina68

The recommended time frame to change your lens case for any brand of contact lens is 3 months.

Three months. Got it.

I'm just curious, porcelina68, how often do you buy new solution? Would that suggestion I heard about getting a new case every time you buy new solution work for you?

Knotlob · #4 (**permalink**) 11-18-2009, 10:00 AM

I realise this is an oldish thread, but apart from the optician's recommendations, why should you change the case very frequently?

I take the lens out of my eye at night, return them to the case and fill with peroxide solution. In the morning I throw out the peroxide and add neutralising solution. After 30mins or so I take the lenses from the case and put them in my eye. So, the lens case is being sterilised every day with peroxide and should kill any bacteria present.

Have been doing this while wearing contacts for at least 30 years without problems.

knotlob

Wendy94 · #5 (**permalink**) 11-18-2009, 10:17 AM

Quote:

Originally Posted by Knotlob

I realise this is an oldish thread, but apart from the optician's recommendations, why should you change the case very frequently?

I take the lens out of my eye at night, return them to the case and fill with peroxide solution. In the morning I throw out the peroxide and add neutralising solution. After 30mins or so I take the lenses from the case and put them in my eye. So, the lens case is being sterilised every day with peroxide and should kill any bacteria present.

Have been doing this while wearing contacts for at least 30 years without problems.

knotlob

That's a very good question, Knotlob. If you sterilize your contact lens case on a regular basis, then theoretically, you should have to replace it for a long time, right?

rfriel · #6 (**permalink**) 12-04-2009, 11:02 AM

Quote:

Originally Posted by Wendy94

That's a very good question, Knotlob. If you sterilize your contact lens case on a regular basis, then theoretically, you shouldn't have to replace it for a long time, right?

for the peroxide, clear care requires 6 hour neutralization, if you can do it in 30 min that's AWESOME, how do you do it. I want to do it this way.

Knotlob · #7 (**permalink**) 12-04-2009, 11:32 AM

Quote:

Originally Posted by rfriel

for the peroxide, clear care requires 6 hour neutralization, if you can do it in 30 min that's AWESOME, how do you do it. I want to do it this way.

To clear up possible confusion. I put my lenses into the case when I go to bed. I add the hydrogen peroxide solution to the case at that point and sterilisation of the lenses takes place overnight. 6 hours seems a long time to sterilise the lenses, but anyway, this way the lenses are sterilised for several hours.

In the morning, when I get up, I empty out the sterilising peroxide solution and refill the case with neutralising solution and give it a shake. I leave this 30 mins to work. Then I insert the contact lenses. I usually just leave the used neutralising solution in the closed case (I leave the case at home) and in the evening I empty out the old solution and refill with peroxide solution (simple!).

One other point. My optician recommended that I should try and wait 45 mins in the morning before putting my lenses in in order to allow my eyes to get as much oxygen as possible. Conventional contact lenses tend to restrict somewhat the oxygen flow to the eyes and over night with the eyes closed the eyes get less oxygen than they do normally in daytime.

knotlob

rfriel · #8 (**permalink**) 12-04-2009, 11:45 AM

do you use the regular store bought non-filtered 3% peroxide solution or a special filtered peroxide solution for contact lens? and what is the name of the neutralizing agent, cause i want to sterilize my lens this way. Acanthomoeba single cell organisms take 4 hours to kill in 3% H2O2 solution, so 6 hours may be required to kill the worst kind of organisms. i did a web search and was looking for the half life of acanthomoeba cell in different solutions, Aquify took min to kill the cell, but 3% H2O2 took 4 hours, YIKES!! and you say the neutralization take only 30 min? that is GREAT news, i like it. also, with 2nd 3rd generation SiH lens, oxygen transmissibility is almost 100%, so it really doesnt matter how long lenses are left in, there is no oxygen deprivation to the corneas, the real issue i see if MK infection after swimming or showering if lens are left in for extended wear and days at a time. i wouldn't do this. thanks for the response.

Droopy · #9 (**permalink**) 12-04-2009, 11:47 AM

Quote:

Originally Posted by Knotlob

One other point. My optician recommended that I should try and wait 45 mins in the morning before putting my lenses in in order to allow my eyes to get as much oxygen as possible. Conventional contact lenses tend to restrict somewhat the oxygen flow to the eyes and over night with the eyes closed the eyes get less oxygen than they do normally in daytime.

knotlob

Thank you for your step-by-step explanation, Knotlob. Sometimes I'm not too bright and I need it spelled out for me.

I also have to say I've never heard of waiting 45 minutes before you put your contacts in each morning. That sounds like a good idea and very refreshing. The only thing is I like so sleep late and so 45 minutes after I get up I'm out the door.

I suppose that gives normal people the time to take a shower, get dressed and have some breakfast before they "put their eyes in." The ladies will also have to "put their face on."

Knotlob · #10 (**permalink**) 12-04-2009, 12:25 PM

Quote:

Originally Posted by rfriel

do you use the regular store bought non-filtered 3% peroxide solution or a special filtered peroxide solution for contact lens? and what is the name of the neutralizing agent, cause i want to sterilize my lens this way. Acanthomoeba single cell organisms take 4 hours to kill in 3% H2O2 solution, so 6 hours may be required to kill the worst kind of organisms. i did a web search and was looking for the half life of acanthomoeba cell in different solutions, Aquify took min to kill the cell, but 3% H2O2 took 4 hours, YIKES!! and you say the neutralization take only 30 min? that is GREAT news, i like it. also, with 2nd 3rd generation SiH lens, oxygen transmissibility is almost 100%, so it really doesnt matter how long lenses are left in, there is no oxygen deprivation to the corneas, the real issue i see if MK infection after swimming or showering if lens are left in for extended wear and days at a time. i wouldn't do this. thanks for the response.

Re the peroxide, I suggest you buy a standard contact lens sterilising solution from your optician, etc. Don't buy something designed for killing algae, etc. in a garden pond!! It may contain impurities like mercury, etc. and may be the wrong strength and will not be the correct isotonic (saline) strength. I live in Germany so I doubt you would find the one my family use. (I do actually make my own peroxide solution, but I am trained as a chemist/chemical engineer, so do know what I am doing. I also use ultra ultra pure water from a laboratory and analar grade salt and hydrogen peroxide to make my solution). I certainly don't recommend people make up their own solutions, as too much can go wrong with potentially serious results.

The same goes for the neutraliser solution - buy that at an optician. Mine is called Eyesee, but that is a German Optician's own/store brand, so will likely not be available in the US. You can use a catalyst, but I don't particularly like them. Some neutralising solutions have preservatives in them that give some people problems. My wife is intolerant to these, so you may need to try different ones. I did live in Canada for 2 years and used the same method, so you should be able to buy the neutralising solution in the US.

Thanks for the info on the half life of the Acanthamoebae. I didn't realise they were so virulent, though I know they are very dangerous. Yes, if you were to get the amoebae on your SiH lens and were wearing it for a month I can see that as a major problem, though I think it only takes 24 h to cause blindness. Hence the importance of not using tap water to put your lenses in. People caution against showering with lenses in, on this forum, but I have never heard of amoebae problems via showering. Maybe the risk is higher in tropical or underdeveloped countries where the supply water temperatures are higher allowing bacteria to breed more easily.

knotlob

Tonythetiger · #11 (**permalink**) 12-04-2009, 02:43 PM

Quote:

Originally Posted by rfriel

Acanthomoeba single cell organisms take 4 hours to kill in 3% H2O2 solution, so 6 hours may be required to kill the worst kind of organisms. i did a web search and was looking for the half life of acanthomoeba cell in different solutions, Aquify took min to kill the cell, but 3% H2O2 took 4 hours, YIKES!! and you say the neutralization take only 30 min? that is GREAT news, i like it. also, with 2nd 3rd generation SiH lens, oxygen transmissibility is almost 100%, so it really doesnt matter how long lenses are left in, there is no oxygen deprivation to the corneas, the real issue i see if MK infection after swimming or showering if lens are left in for extended wear and days at a time. i wouldn't do this. thanks for the response.

That's some really good information there, rfriel. Thank you for posting it. It looks like Knotlob approves, too. Where did you get that data from?

You said "half life." Are amoebas like radioactive material. If their half-life is 30 minutes in Solution X, does that mean that if you've got 100 amoebas, half an hour later you'll have 50, and then after another 30 minutes you'll have 25 and so on?

Knotlob · #12 (**permalink**) 12-04-2009, 05:45 PM

Quote:

Originally Posted by Tonythetiger

That's some really good information there, rfriel. Thank you for posting it. It looks like Knotlob approves, too. Where did you get that data from?

You said "half life." Are amoebas like radioactive material. If their half-life is 30 minutes in Solution X, does that mean that if you've got 100 amoebas, half an hour later you'll have 50, and then after another 30 minutes you'll have 25 and so on?

Yes, that is how I would interpret the half life of the amoebae.

knotlob

Knotlob · #13 (**permalink**) 12-04-2009, 06:28 PM

Quote:

Originally Posted by rfriel

snip ...
Acanthomoeba single cell organisms take 4 hours to kill in 3% H2O2 solution, so 6 hours may be required to kill the worst kind of organisms. i did a web search and was looking for the half life of acanthomoeba cell in different solutions, Aquify took min to kill the cell, but 3% H2O2 took 4 hours, YIKES!! and you say the neutralization take only 30 min? that is GREAT news, i like it. also, with 2nd 3rd generation SiH lens, oxygen transmissibility is almost 100%, so it really doesnt matter how long lenses are left in, there is no oxygen deprivation to the corneas, the real issue i see if MK infection after swimming or showering if lens are left in for extended wear and days at a time. i wouldn't do this. thanks for the response.

Hello rfriel

Your post has sent me off in search of further information on these nasty Acanthamoeba.kerititis critters and what I find doesn't make me a Happy Bunny!!

Anyway, there are a lot of difficult to read scientific research papers on the Internet with regard to the amoeba and contact lenses. Here is a typical one:

http://jmm.sgmjournals.org/cgi/reprint/57/11/1399.pdf

Incidences of Acanthamoeba infection have increased greatly in recent years due to the rise in popularity of (soft) contact lenses.

The amoeba is present everywhere it seems, not just in obviously polluted water, but in brackish, sea, bottled and tap water, earth, air, in dust around the home, etc.

Not all Acanthamoeba are pathogenic (dangerous to man).

Infections are usually caused by poor contact lens and case cleaning regimes. Using tap water to wash out your lens case or to put the lenses into your eye is a serious contributor to infection. Also amongst people who make up their own saline solution using tap water in non-sterile conditions.

Tap water in hard water (limestone) areas seem to encourage Acanthamoeba growth.

Hydrogen peroxide systems based on 'one step' using a catalyst are not very effective against Acanthamoeba, because as you have said, the Acathamoeba is quite resistant and it needs time to be destroyed. The catalyst system starts to reduce the strength of the Hydrogen Peroxide solution immediately and reduces it's effectiveness. The two step hydrogen peroxide plus a neutraliser seems more effective countering Acanthamoeba.

Heat treatment is the most effective at killing the amoeba but that of course cannot be used for silicone hydrogel lenses.

Multi Purpose Contact Lens (Maintenance) Solutions containing polyhexamethylene biguanide (PHMB) or chlorhexidine digluconate, were often not concentrated enough to ensure protection against the Acanthamoeba contamination.

Daily disposables were considered to be the safest option.

It was not recommended to swim (unless with goggles), shower, use a hot tub, or do water sports wearing contact lenses. If you did do these wearing lenses, then the lenses should be removed immediately afterwards and sterilised.

Before handling the lenses, hands should be thoroughly washed AND dried.

The lens case should be rinsed in sterile water (or sterile lens solution) and air dried.

These recommendations although sensible, do seem to err on the side of caution. It does beg the question 'Will we see an increase in Acanthamoeba infection amongst people who choose to wear high permeability monthly disposable Silicone Hydrogel lenses 24/7 and swim, shower, do water sports, etc. etc? Or perhaps the manufacturers have designed some mechanism into the silicone hydrogel to counter this threat?

Food for thought!

knotlob

Knotlob · #14 (**permalink**) 12-04-2009, 06:33 PM

Quote:

Originally Posted by rfriel

for the peroxide, clear care requires 6 hour neutralization, if you can do it in 30 min that's AWESOME, how do you do it. I want to do it this way.

Hi rfriel

I just reread your post - I guess the Clear Care system you refer to is a 3% hydrogen peroxide solution with a catalyst - so called one step system. It takes a while for the catalyst to breakdown the peroxide before you can put the lens in your eye, but please see in my previous post - the one step hydrogen peroxide system seems to lack effectiveness against Acanthamoeba.

knotlob

rfriel · #15 (**permalink**) 12-09-2009, 10:23 AM

The 2 step H2O2 disinfection system really is the only way to kill the nasty acanthomoeba cell. thanks for the link to the additional research paper on this topic, very interesting. this thread has prompted me to change to the 2 step H2O2 system to disinfect my lenses. just found this research paper that confirms 2 step H2O2 is effective against acanthamoeba if un neutralized contact is permitted for at least 4 hours. happy reading?? http://aac.asm.org/cgi/content/full/45/7/2038#F1

HelpMeRhonda · #16 (**permalink**) 12-09-2009, 11:03 AM

The Southern United States has all kinds of nasty venomous snakes and spiders, but such things are pretty rare in the North. Are amoebas unevenly distributed like this or are they just everywhere?

Knotlob · #17 (**permalink**) 12-09-2009, 12:43 PM

Quote:

Originally Posted by HelpMeRhonda

The Southern United States has all kinds of nasty venomous snakes and spiders, but such things are pretty rare in the North. Are amoebas unevenly distributed like this or are they just everywhere?

As far as I know these cute little Acanthamoeba exist everywhere (air, earth, water [bottled, tap, brackish, sea, fresh, swimming pools, hot tubs, etc]).

Whether you suffer an infection or not is more likely to be due to the actual population of amoebae. One or two are probably not going to have much effect on you, but in the research papers they are quoting 1000 - 10,000 amoebae - but that was for disinfection tests with peroxide, etc.

Regular disinfection and lens case cleaning will minimise the population count. As to the worst places, I haven't seen any published data but would expect that these creatures breed best where the conditions are warm and moist. i.e. tropical humid areas, rather than the Arctic Circle in the middle of winter. But as living standards improve, peoples' houses are probably warmer, etc. Same sort of problem as for asthma sufferers.

knotlob

Knotlob · #18 (**permalink**) 12-09-2009, 01:10 PM

Quote:

Originally Posted by rfriel

The 2 step H2O2 disinfection system really is the only way to kill the nasty acanthomoeba cell. thanks for the link to the additional research paper on this topic, very interesting. this thread has prompted me to change to the 2 step H2O2 system to disinfect my lenses. just found this research paper that confirms 2 step H2O2 is effective against acanthamoeba if un neutralized contact is permitted for at least 4 hours. happy reading?? http://aac.asm.org/cgi/content/full/45/7/2038#F1

Thanks rfriel for that link. Quite useful and as you say. At least full disinfection can be completed in 4 hours with the 2 step system, so I can still put the lenses back in my eyes after a short night if I have to!

knotlob

rfriel · #19 (**permalink**) 12-09-2009, 01:11 PM

the 1 step H2O2 disinfection system can be turned into 2 step, by simply pulling off the disk from the container and placing the lenses into the H2O2 for 6 hours, then, placing the disk back on and allowing another 6 hours for disinfection. this is probably prohibitilvey long for disinfection, SO i may just change to a 2 step system, with neutralizer disk after 30 mins

Knotlob · #20 (**permalink**) 12-09-2009, 01:35 PM

Quote:

Originally Posted by rfriel

the 1 step H2O2 disinfection system can be turned into 2 step, by simply pulling off the disk from the container and placing the lenses into the H2O2 for 6 hours, then, placing the disk back on and allowing another 6 hours for disinfection. this is probably prohibitilvey long for disinfection, SO i may just change to a 2 step system, with neutralizer disk after 30 mins

Not sure how the cost works out on each system. Certainly the catalyst has to be changed periodically. The advantage of the two step solution is that the neutralisation, when applied, is quite fast.

There is the risk of forgetting to neutralise, but once you follow a habit, it isn't a problem. I think I've only forgotten to neutralise the peroxide once or twice in 30 years. A short sharp lesson!

knotlob

rfriel · #21 (**permalink**) 12-09-2009, 01:40 PM

only happens once, you never, ever for the pain of that experience. AND yes, 2 step with neutralizing disk is much faster to get the lenses in your eye, and not have to wait for another 6 hours.

Enah · #22 (**permalink**) 12-09-2009, 02:19 PM

Quote:

Originally Posted by rfriel

only happens once, you never, ever for the pain of that experience. AND yes, 2 step with neutralizing disk is much faster to get the lenses in your eye, and not have to wait for another 6 hours.

Yes, I would imagine that putting a contact lens in your eye that still had unneutralized H2O2 on it would make a lasting impression.

rfriel · #23 (**permalink**) 12-09-2009, 02:54 PM

those with OCD, you could use 2 sets of lenses at any one time, take one full day to disinfect and neutralize one set and wear the other set, then just rotate on a daily basis. discard after you have worn the lenses the # of days prescribed by the manufacturer. a full day in H2O2 aught to kill any germ in the container, No?, then neutralize overnight for an extremely clean set of lenses the next day, and do the same with the other set of lenses. No? of course, this is just for extreme germophobes and those with OCD..........

rfriel · #24 (**permalink**) 12-09-2009, 02:58 PM

i think that's what lit is saying, same as 3dB point in signal analysis of bandpass filters

also, the half life is found in the articles specified above

Quote:

Originally Posted by Tonythetiger

That's some really good information there, rfriel. Thank you for posting it. It looks like Knotlob approves, too. Where did you get that data from?

You said "half life." Are amoebas like radioactive material. If their half-life is 30 minutes in Solution X, does that mean that if you've got 100 amoebas, half an hour later you'll have 50, and then after another 30 minutes you'll have 25 and so on?

Steuhrob · #25 (**permalink**) 12-09-2009, 03:11 PM

Quote:

Originally Posted by rfriel

i think that's what lit is saying, same as 3dB point in signal analysis of bandpass filters

Uuuummmm . . . what?? Are we still talking about protecting the eyes from amoeba invasion?

rfriel · #26 (**permalink**) 12-09-2009, 03:17 PM

Quote:

Originally Posted by Steuhrob

Uuuummmm . . . what?? Are we still talking about protecting the eyes from amoeba invasion?

sometimes i get off topic and start to ramble, but yes, i think log -3 kill is half life of anything, radioactive material, cells, germs, half life of a hot dog when i am eating it. something like that, but it can be checked in the literature (lit) specified as well.....

Knotlob · #27 (**permalink**) 12-09-2009, 04:34 PM

Quote:

Originally Posted by rfriel

sometimes i get off topic and start to ramble, but yes, i think log -3 kill is half life of anything, radioactive material, cells, germs, half life of a hot dog when i am eating it. something like that, but it can be checked in the literature (lit) specified as well.....

What an erudite discussion

Log (to the base 10 ) of 3, is 0.477 (i.e. almost 0.5 so that sounds about right.

knotlob

Wendy94 · #28 (**permalink**) 12-09-2009, 05:21 PM

Quote:

Originally Posted by Knotlob

What an erudite discussion

Log (to the base 10 ) of 3, is 0.477 (i.e. almost 0.5 so that sounds about right.

knotlob

Hey, nobody told me there'd be math on this thread!

Can you put that in plain English so the non-scientists on Lens 101 can join in the discussion? This may need to be put into its own thread.

Knotlob · #29 (**permalink**) 12-10-2009, 05:04 AM

Quote:

Originally Posted by Wendy94

Hey, nobody told me there'd be math on this thread!

Can you put that in plain English so the non-scientists on Lens 101 can join in the discussion? This may need to be put into its own thread.

I'm getting a bit rusty with the logs and exponentials myself

Scientists use log function expressions to deal with very large numbers. So in simple terms 10, 100, 1000, 10,000 in log (base 10) would represented as 1, 2, 3, 4, etc. They are discussing colonies of bacteria and the numbers could get very large.

It's not important for the lay person to understand the technicalities, just learn from the conclusions of their studies and keep your lenses clean with the most appropriate disinfection regime

knotlob

rfriel · #30 (**permalink**) 12-10-2009, 12:03 PM

2 step H2O2 is the only contact lens disinfection system that will kill one of the most difficult to kill creatures to cause eye infections. cysts of acanthamoeba. any other contact lens cold disinfection system will not work. so there you have it.... good day

Knotlob · #31 (**permalink**) 12-10-2009, 03:36 PM

Quote:

Originally Posted by rfriel

2 step H2O2 is the only contact lens disinfection system that will kill one of the most difficult to kill creatures to cause eye infections. cysts of acanthamoeba. any other contact lens cold disinfection system will not work. so there you have it.... good day

Well said. You could use a heat system to kill the creatures, but that is inconvenient for the majority of contact lens users (it used to be a standard method when I got my hard lenses) but it is not suitable for silicone hydrogel contact lenses.

knotlob

rfriel · #32 (**permalink**) 12-16-2009, 10:40 AM

i just put my aquify lens case overnight in H2O2 for disinfection. completely submerged, case, lids. i hope this helps disinfect the lens case, any objections?? i'd love to hear dissents, agreements, anyone. is this really bad to do??

Knotlob · #33 (**permalink**) 12-16-2009, 12:14 PM

Quote:

Originally Posted by rfriel

i just put my aquify lens case overnight in H2O2 for disinfection. completely submerged, case, lids. i hope this helps disinfect the lens case, any objections?? i'd love to hear dissents, agreements, anyone. is this really bad to do??

That should work fine, provided you use the two step system of peroxide to ensure maximum peroxide strength (3%) for the duration of the lens case sterilisation.

knotlob

rfriel · #34 (**permalink**) 12-16-2009, 12:22 PM

if the H2O2 will soak into the lens case and be released when i soak my lenses next time in aquify and render the lens unusable because H2O2 3% has mixed with the solution and gotten on the lenses? i have rinsed the case a few times in sterile saline and aquify solution but in dont know if that is enough??

Quote:

Originally Posted by Knotlob

That should work fine, provided you use the two step system of peroxide to ensure maximum peroxide strength (3%) for the duration of the lens case sterilisation.

knotlob

Railfan · #35 (**permalink**) 12-16-2009, 12:52 PM

Quote:

Originally Posted by Knotlob

As far as I know these cute little Acanthamoeba exist everywhere (air, earth, water [bottled, tap, brackish, sea, fresh, swimming pools, hot tubs, etc]).

knotlob

I hope this will discourage those who would post a thread saying that you can clean your contacts with a quick rinse of tap water.

Knotlob · #36 (**permalink**) 12-16-2009, 01:17 PM

Quote:

Originally Posted by rfriel

if the H2O2 will soak into the lens case and be released when i soak my lenses next time in aquify and render the lens unusable because H2O2 3% has mixed with the solution and gotten on the lenses? i have rinsed the case a few times in sterile saline and aquify solution but in dont know if that is enough??

Your case should not be very porous for hygiene reasons, I would have thought. Just drain off the peroxide and rince with sterile saline or your normal lens solution. Hydrogen Peroxide will likely breakdown into harmless by-products (water & oxygen) over time, but in any case, the dilution with the new saline/lens solution will ensure there in no discomfort on your eyes/lenses.

knotlob

Droopy · #37 (**permalink**) 12-18-2009, 03:27 PM

Quote:

Originally Posted by Knotlob

Your case should not be very porous for hygiene reasons, I would have thought. Just drain off the peroxide and rince with sterile saline or your normal lens solution. Hydrogen Peroxide will likely breakdown into harmless by-products (water & oxygen) over time, but in any case, the dilution with the new saline/lens solution will ensure there in no discomfort on your eyes/lenses.

knotlob

That makes sense, Knotlob. Most contact lens cases are made of plastic, which isn't very porous and will not soak up or hold H2O2.

Railfan · #38 (**permalink**) 12-28-2009, 12:28 PM

Quote:

Originally Posted by Droopy

That makes sense, Knotlob. Most contact lens cases are made of plastic, which isn't very porous and will not soak up or hold H2O2.

Is that true? The plastic lens cases will not absorb hydrogen peroxide?

Knotlob · #39 (**permalink**) 12-28-2009, 12:54 PM

Quote:

Originally Posted by Railfan

Is that true? The plastic lens cases will not absorb hydrogen peroxide?

You would rwally need to try with some coloured water. But if I were designing/specifying a contact lens case (or any other piece of reusable medical equipment where sterility was important) I would certainly specify that it was non-porous so as not to absorb any fluids, etc.

knotlob

Enah · #40 (**permalink**) 12-30-2009, 12:10 PM

Quote:

Originally Posted by Knotlob

It's not important for the lay person to understand the technicalities, just learn from the conclusions of their studies and keep your lenses clean with the most appropriate disinfection regime

knotlob

Pay no attention to that man behind the curtain!

Knotlob · #41 (**permalink**) 12-30-2009, 12:21 PM

Quote:

Originally Posted by Enah

Pay no attention to that man behind the curtain!

I'll try not to - but what a spooky picture!

knotlob

Hottchick · #42 (**permalink**) 12-30-2009, 03:14 PM

Quote:

Originally Posted by Knotlob

I'll try not to - but what a spooky picture!

knotlob

Yeah, no kidding. This is one of the things that really scared me watching "The Wizard of OZ" as a kid. That and they flying monkeys.

I'll get you my pretty! And your little dog, too!

rfriel · #43 (**permalink**) 01-04-2010, 05:35 PM

the only way to really sterilize your lens are to soak lenses overnight in sterile, filtered H2O2, then neutralize the H2O2 before wearing, to sterilize lens case, submerge case and lids into filtered H2O2, overnight, then fill case with sterile saline and place the neutralizer disk in the lens case overnight to neutralize any H2O2 absorbed into the lens case. yeah, this is overkill, but then you can be assured the nasty acanthamoeba protazoa is neutralized, the worst possible bacterial infection to kill for contact lens wearers, oh, and be on the look out for the trauma to epithelial layer as shown by forencien staining, this will identify weaknesses in the epi layer which is required for bacterial infection to occur in contact lense wear, the epi must be comprimised before bacteria can infect the eye.

Otherwise, happy contact lens wearing???

K-9 · #44 (**permalink**) 01-05-2010, 10:30 AM

Wow. This post has been up for just over a year and has about 40 responses and has been viewed nearly a thousand times! Great question, HelpMeRhonda!

rfriel · #45 (**permalink**) 01-05-2010, 10:39 AM

we are only discussing degree of porosity, contact lens and case will be infilterated by H2O2, or any other MPD solution. that is why staining of the epi layer occurs.

Quote:

Originally Posted by Railfan

Is that true? The plastic lens cases will not absorb hydrogen peroxide?

dragongirl81 · #46 (**permalink**) 01-05-2010, 02:56 PM

Quote:

Originally Posted by Hottchick

Yeah, no kidding. This is one of the things that really scared me watching "The Wizard of OZ" as a kid. That and they flying monkeys.

I'll get you my pretty! And your little dog, too!

Flying monkeys. *Shudder*

K-9 · #47 (**permalink**) 01-13-2010, 03:46 PM

Quote:

Originally Posted by rfriel

we are only discussing degree of porosity, contact lens and case will be infilterated by H2O2, or any other MPD solution. that is why staining of the epi layer occurs.

Okay, slow down a little. Will the contact lens solution be in this porous case long enough for there to be any infiltration? What's any "epi layer"? Is that part of the contact lens or the case?

Knotlob · #48 (**permalink**) 01-13-2010, 04:41 PM

Quote:

Originally Posted by K-9

Okay, slow down a little. Will the contact lens solution be in this porous case long enough for there to be any infiltration? What's any "epi layer"? Is that part of the contact lens or the case?

I previously said that if I were designing the lens case I would ensure it was Non-Porous (for hygiene reasons). I think the lens case manufacturers will have been intelligent enough to figure that one out. I suppose you could put some beetroot juice, or similar, into an old clean case and see if the case is stained after overnight soaking (we will ignore the molecular size difference between the beetroot juice dye and the hydrogen peroxide initially).

I think rfriel is possibly referring to cornea epithelial layer when quoting 'epi'. It is part of the eye, not the contact lens or case.

knotlob

rfriel · #49 (**permalink**) 01-14-2010, 10:46 AM

Quote:

Originally Posted by Knotlob

I previously said that if I were designing the lens case I would ensure it was Non-Porous (for hygiene reasons). I think the lens case manufacturers will have been intelligent enough to figure that one out. I suppose you could put some beetroot juice, or similar, into an old clean case and see if the case is stained after overnight soaking (we will ignore the molecular size difference between the beetroot juice dye and the hydrogen peroxide initially).

I think rfriel is possibly referring to cornea epithelial layer when quoting 'epi'. It is part of the eye, not the contact lens or case.

knotlob

Yes, correct, floursein staining can detect degradation of the epithelial layer due to contact lens and case absorbing the disinfection solution. OK, i agree, the case may not be as porous at the contact lens material itself, but when the epi layer is comprimised, infection can get into the cornea. an uncomprimised epi layer is the best defense against eye infection and some some disinfection systems will harm the epi layer more than others, that is why flourensien staining is important to check to determine how much of the epi layer is damaged by either the lens case or contact lens absorbing the toxic chemicals and then getting into the eye and damaging the epi layer to increase infection probability. YUCK!!

this makes me very sad, i feel like crying

Knotlob · #50 (**permalink**) 01-14-2010, 12:24 PM

Quote:

Originally Posted by rfriel

Yes, correct, floursein staining can detect degradation of the epithelial layer due to contact lens and case absorbing the disinfection solution. OK, i agree, the case may not be as porous at the contact lens material itself, but when the epi layer is comprimised, infection can get into the cornea. an uncomprimised epi layer is the best defense against eye infection and some some disinfection systems will harm the epi layer more than others, that is why flourensien staining is important to check to determine how much of the epi layer is damaged by either the lens case or contact lens absorbing the toxic chemicals and then getting into the eye and damaging the epi layer to increase infection probability. YUCK!!

this makes me very sad, i feel like crying

Hi rfriel

I was at the opticians today for a fitting of RGP lenses, so asked a load of other questions. She, like me, thought that the case would be non-porous being a medical device container, but had probably given it little thought.

I think you should be more concerned about deposits inside the lens case, which may be able to harbour the bacteria you are talking about. I just don't see a lens case absorbing disinfectant materials and if it did, then maybe people would know about it when they put a 'neutralised' peroxide disinfected lens into their eye. i.e. when they neutralise the lenses after disinfecting, the case will certainly be fully neutralised of any hydrogen peroxide.

knotlob

rfriel · #51 (**permalink**) 01-14-2010, 01:50 PM

Quote:

Originally Posted by Knotlob

Hi rfriel

I was at the opticians today for a fitting of RGP lenses, so asked a load of other questions. She, like me, thought that the case would be non-porous being a medical device container, but had probably given it little thought.

I think you should be more concerned about deposits inside the lens case, which may be able to harbour the bacteria you are talking about. I just don't see a lens case absorbing disinfectant materials and if it did, then maybe people would know about it when they put a 'neutralised' peroxide disinfected lens into their eye. i.e. when they neutralise the lenses after disinfecting, the case will certainly be fully neutralised of any hydrogen peroxide.

knotlob

I agree, you are correct, knotlob. lens case contamination is a big problem, probably more so than lens case porosity or lens porosity. that is why weekly, i put my lens case in H2O2 overnight, to disinfect the lens case.

Knotlob · #52 (**permalink**) 01-14-2010, 02:06 PM

Quote:

Originally Posted by rfriel

I agree, you are correct, knotlob. lens case contamination is a big problem, probably more so than lens case porosity or lens porosity. that is why weekly, i put my lens case in H2O2 overnight, to disinfect the lens case.

What do you put your lenses in when you do the nightly disinfection?

I just use the lens case (double basket in a single container) and disinfect with peroxide each night. That way the case is disinfected every night. Do you use a separate case for daytime and another for nightly disinfection?

I just wondered based on forum member's comments re disinfecting their lens cases

knotlob

rfriel · #53 (**permalink**) 01-14-2010, 02:57 PM

Quote:

Originally Posted by Knotlob

What do you put your lenses in when you do the nightly disinfection?

I just use the lens case (double basket in a single container) and disinfect with peroxide each night. That way the case is disinfected every night. Do you use a separate case for daytime and another for nightly disinfection?

I just wondered based on forum member's comments re disinfecting their lens cases

knotlob

Yes, i guess my response does need further explanation. i use clearcare (i.e. AOsept) for nightly disinfection, i have a separate lens case that i use during the day if my lens need refreshing via focus aqua (i.e. aquify), somedays, if my lens are irritating the eye, pop lens out put in aquify for 10 min, rinse off and pop lens back in, yeah, most think its a hassle?? not when it takes less than 1 min to pop lense out and 30 sec to pop lens in, no problem, and i dont have to do it every day, just some days. eye allergies are very inconsistant, some days are great, no irritation and some days are really sucky, that's when i have to take zyrtec or benedryl so my eyes dont get too irritated. so there you have it

dragongirl81 · #54 (**permalink**) 02-11-2010, 02:42 PM

Quote:

Originally Posted by rfriel

Yes, i guess my response does need further explanation. i use clearcare (i.e. AOsept) for nightly disinfection, i have a separate lens case that i use during the day if my lens need refreshing via focus aqua (i.e. aquify), somedays, if my lens are irritating the eye, pop lens out put in aquify for 10 min, rinse off and pop lens back in, yeah, most think its a hassle?? not when it takes less than 1 min to pop lense out and 30 sec to pop lens in, no problem, and i dont have to do it every day, just some days. eye allergies are very inconsistant, some days are great, no irritation and some days are really sucky, that's when i have to take zyrtec or benedryl so my eyes dont get too irritated. so there you have it

Thanks for sharing your routine with is rfriel. I wonder how many people do things the same way you do?

Knotlob · #55 (**permalink**) 02-11-2010, 05:25 PM

Quote:

Originally Posted by rfriel

Yes, i guess my response does need further explanation. i use clearcare (i.e. AOsept) for nightly disinfection, i have a separate lens case that i use during the day if my lens need refreshing via focus aqua (i.e. aquify), somedays, if my lens are irritating the eye, pop lens out put in aquify for 10 min, rinse off and pop lens back in, yeah, most think its a hassle?? not when it takes less than 1 min to pop lense out and 30 sec to pop lens in, no problem, and i dont have to do it every day, just some days. eye allergies are very inconsistant, some days are great, no irritation and some days are really sucky, that's when i have to take zyrtec or benedryl so my eyes dont get too irritated. so there you have it

Hello rfriel

Thanks for the clarification. That was helpful

.

knotlob

Enah · #56 (**permalink**) 03-18-2010, 04:40 PM

Quote:

Originally Posted by Hottchick

Yeah, no kidding. This is one of the things that really scared me watching "The Wizard of OZ" as a kid. That and they flying monkeys.

I'll get you my pretty! And your little dog, too!

I hope I haven't scared you and knotlob too badly.

You seem to have recovered enough to continue posting.

SopranoKris · #57 (**permalink**) 03-02-2011, 04:06 PM

OK, all this talk of acanthomoeba has me completely paranoid. I have never even heard of H2O2 disinfecting. Is that something that's only available in Europe?

All I have is a one step solution (Opti-Free RepleniSH).

Should I talk to my eye doctor about an H2O2 disinfection system? Can I use them with silicon hydrogels? (I have Biofinity Torics)

The germophobe in me is freaking out right now!!!!

DebiK · #58 (**permalink**) 03-03-2011, 10:21 AM

Quote:

Originally Posted by SopranoKris

OK, all this talk of acanthomoeba has me completely paranoid. I have never even heard of H2O2 disinfecting. Is that something that's only available in Europe?

All I have is a one step solution (Opti-Free RepleniSH).

Should I talk to my eye doctor about an H2O2 disinfection system? Can I use them with silicon hydrogels? (I have Biofinity Torics)

The germophobe in me is freaking out right now!!!!

I found a question-and-answer page about Opti-Free solution. Here's the part I want to tell you about:

Has OPTI-FREE® RepleniSH® been tested against Acanthamoeba?

Yes, OPTI-FREE® RepleniSH® MPDS has demonstrated activity against Acanthamoeba.

Tell the germophobe in you to relax. Keep him or her around though, to make sure you keep your contacts clean.

I'm not sure about that hydrogen peroxide question. I couldn't find anything on line that clearly said "you can clean Opti-Free Replenish contact lenses in hydrogen peroxide." Best thing is to just ask your doctor.

SopranoKris · #59 (**permalink**) 03-03-2011, 11:09 AM

Quote:

Originally Posted by DebiK

I found a question-and-answer page about Opti-Free solution. Here's the part I want to tell you about:

Has OPTI-FREE® RepleniSH® been tested against Acanthamoeba?

Yes, OPTI-FREE® RepleniSH® MPDS has demonstrated activity against Acanthamoeba.

Tell the germophobe in you to relax. Keep him or her around though, to make sure you keep your contacts clean.

I'm not sure about that hydrogen peroxide question. I couldn't find anything on line that clearly said "you can clean Opti-Free Replenish contact lenses in hydrogen peroxide." Best thing is to just ask your doctor.

OK, I feel a bit better now, thanks so much for your response!

I have to go back to my OD to place my lense order, so I'll ask about H2O2 disinfecting when I'm there.

Aaroncablemom · #60 (**permalink**) 03-03-2011, 11:51 AM

Quote:

Originally Posted by SopranoKris

OK, I feel a bit better now, thanks so much for your response!

I have to go back to my OD to place my lense order, so I'll ask about H2O2 disinfecting when I'm there.

Will you let us know what your OD says? I'm sure you're not the only one who is wondering.

HelpMeRhonda · #61 (**permalink**) 10-27-2011, 02:55 PM

Quote:

Originally Posted by SopranoKris

OK, I feel a bit better now, thanks so much for your response!

I have to go back to my OD to place my lense order, so I'll ask about H2O2 disinfecting when I'm there.

Cool. I'm glad Lens 101 was helpful to you.

Aaroncablemom · #62 (**permalink**) 11-07-2011, 05:55 PM

Quote:

Originally Posted by SopranoKris

OK, I feel a bit better now, thanks so much for your response!

I have to go back to my OD to place my lense order, so I'll ask about H2O2 disinfecting when I'm there.

So what did your OD say about hydrogen peroxide disinfecting for your contact lenses?

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