Silicone Hydrogels - 2 Week vs Monthly?

[Skagen]

I'm a long time user of CSI daily wears, but as they as now discontinued in my prespecription I am now looking at the new lenses being used these days.

I find myself however, unable to "get" the distinction between the variations of silicone hydrogels that I see marketed for 2-week use and montly use. For example - in the UK at least - Ciba Focus Night and Day is primarily prescribed and used as a disposable lens. What then is the reason why there is also a Ciba O2 Optix Lens marketed for 2 week use?

I see that the Optix lens is a variation on the same material and with lower oxygen transmisisibity. So why bother, if most people are already using the Night and Day for the same purpose. Can any advatage be ascribed to the newer variation (02 Optix).

I'm just using these two lenses as an example, but I'm curious if anyone here can explain to me why the companies are marketing what seems to be more or less the same thing.

[drk]

Marketing, brand positioning, differentiation. All that businessy stuff.

O2O has significantly less cost.

[Happylady]

They are different. I wear the Night%Day. My daughter tried them but they weren't comfortable for her. She was fit into the O2 Optix and does very well with them.

It is like why should there be Toyota Camry, Honda Accord, and Ford Taraus? They are all mid size cars that are very similar on paper, aren't they? But really, there are differences between them.

In the states the Night%Day is a 30 day lens. We have many patients that remove them every night, though. We always recommend they be removed at least once a week overnight.

The O2 Optix is a 2 week lens.

[Skagen]

As someone who is definitely going to use lenses for daily use only, is there ANY reason why the Night & Day would be on the radar for someone such as myself?

I ask because I see a huge price difference vs O2 Optix and yet functionally major difference I can discern from the specs is that the Oxygen transmissibility a bit higher on Night & Day and watercontent marginally lower. Can there be THAT much difference in the resulting fit to warrant making a whole new lens and brand?

Sorry to persist in the question, but the positioning just seems very odd to me. Is this because of the past history of lawsuits for companies selling same lens as two different things?

[SpecialT]

As someone who is definitely going to use lenses for daily use only, is there ANY reason why the Night & Day would be on the radar for someone such as myself?

If you have ocular problems associated with a lack of oxygen to your eye, the night and day would be a likely candidate. Only your doctor could tell you if you suffer from such complications. Also, the Night and Day does not deposit easily which coupled with high oxygen transmissability is the reason that it was approved by the FDA to be slept in for a maximum of 30days/nights. Again, only your doctor can tell you what you should do.

Is it the lens for you, I don't know. But there are reasons for a doctor to select the Night and Day to be fit other than just because a person wants to sleep in their lenses.

[Skagen]

I don't have occular problems due to oxgen deficiency and I'm not looking for a lens recommendation. I'm trying to understand what the different properties of these two lenses are - and if there is any effective difference in daily use.

Also I wouldn't agree that the doctor "tells" you what to do. At the end of the day a medical professional gives you advice. Its up to the patient to educate themselves and understand what is embedded in that advice. After all its your eyeballs, you can't sit there on auto-pilot.

[drk]

Skagen, you bring up a few valid points.

From a daily wear viewpoint, the O2O is clearly superior, with everything factored in: cost and frequency of replacement are the dominating factors, but the lens edge design is slightly upgraded, and I do believe they are somewhat thinner (could be wrong). They are generally less stiff and more comfortable. Any decrease in oxygen transmission or change in dehydration rate will be minimal.

From an extended wear viewpoint, there is arguably a difference, but I know that's not the perspective you are coming from, right? The predominant difference is FDA indication for use.

Yes, there have been legal ramifications from selling similar lenses at different prices, so that is a factor when these companies design their product lines.

A cynical, but I think, probable, explanation as to the existence of the O2O, is that the "continuous wear" modality that the Night & Day has been designed for is a "premium" one, and until recently, an exclusive one for Ciba, that has commanded a higher market price. There was stiff competition from Acuvue for a "workhorse/for the masses" silicone-hydrogel daily wear product, so the O2O was launched to fit this "niche". This allows them to not kill the goose that laid the golden egg, so to speak (Night & Day). Interestingly, B&L's Purevision product has been re-launched as an "omni-lens" and has been priced very nicely to compete with the Night and Day and the Acuvue products. Ergo, expect Ciba to lower the Night & Day product's price in the future.

Despite what you may think about your oxygen needs, I think virtually everyone benefits from these hyper-permeable lenses, at some level.

As to the philosophy that you have to control all aspects of your healthcare, yes, technically, I agree. From a practical perspective, I question the efficiency of patients' pre-visit research. If you trust the doc, you should go with the recommendation, or time for a new doc, right?

[Skagen]

drk, thanks for your points. I'm a management consultant and I really find the positioning issue fascinating from that point of view, in addition to exploring it for my personal decision making.

Also don't get me wrong. I do think the oxygen issue is important - in fact that is why I am taking the initiative to look at Silicone Hydrogels. My OD in fact seemed to be neutral between these SH lenses and the older generation hydrogels, which have far less oxygen transmissibility. So I do care - it was my asking that got us towards these lenses in the first place.

As far as he was concerned, if he stocks a lens, its because he is comfortable with prescribing it - and I don't have special needs or condition, so they are all in the frame for chosing.

Added to which, within Silicone hydrogels, he seems perfectly willing to prescribe any of the available brands to me, as long as they feel comfortable . I asked him what he felt the differences between the lenses was and he doesn't seem to think there is any material difference between them.

So there is not really any question of "trust" with the doc, he's not pushing me one way or another. We tried Accuvue Advance and it was fine physical comfort-wise but unfortunately I had the "halo" issue at night with that lens, which he said beforehand is known to occur with some folks, so he threw the field open after I 'd trialled that for a couple of weeks. Which is where I am right now..




If he's going to base it on how comfortable they feel to me, then its best I myself understand a bit more about what is under the hood - and what might be embedded in my decision.

[SpecialT]

I appreciate your desire to inform yourself. When I stated that only your doctor can tell you what you should do, I meant it in terms of a professional opinion. But don't be mistaken, the doctor does make the decision on which lens is prescribed. However, you are absolutely right that ultimately you are in charge of you care and whether to accept the prescription or not.

Back to the lenses... I was trying to say that the Night and Day is a little more resistant to protien deposit than the O2 Optix. Since you apparently don't have Oxygen issues and don't want to sleep in your lenses, the other reasons to go with a Night and Day over the O2 Optix is minimal. drk mentioned lens design which is also a difference. The O2 Optix has a bi-aspheric design which is meant to improve clarity of site and comfort of the lens. To my knowledge, the Night and Day is not designed as such. Lastly, with everything else the same, a brand new lens every 2 weeks is healthier than replacing a lens every 30 days.

In short, they are both great lenses. For my patients in daily wear, I almost always give the nodd to the Optix over the Night and Day.

Good Luck!

[William Stacy O.D.]

As someone who is definitely going to use lenses for daily use only, is there ANY reason why the Night & Day would be on the radar for someone such as myself?

I ask because I see a huge price difference vs O2 Optix and yet functionally major difference I can discern from the specs is that the Oxygen transmissibility a bit higher on Night & Day and watercontent marginally lower. Can there be THAT much difference in the resulting fit to warrant making a whole new lens and brand?

Sorry to persist in the question, but the positioning just seems very odd to me. Is this because of the past history of lawsuits for companies selling same lens as two different things?

The latest thinking on this is that the more oxygen the better for long term survivability of the corneal endothelium. You only get 1 layer of these unique little cells who's sole purpose is to keep your corneas clear. Loose enough of them and you risk blindness and/or corneal transplantation in your later life. So if there is no reason not to go for more O2, then just do it. Your endo will thank you. (anyone who says they don't have an 02 problem and is wearing hydrogels is kidding themselves, or just hasn't attended the right meeting yet, or their Doc hasn't)

[William Stacy O.D.]

I forgot to add that the latest info on this is that all those hydrogels we used to think were safe are actually damaging the endothelial cells, slowly, inexoribly, year after year. They actually morph into freak cells that can't pump water out of the cornea. And this is happening to previously NORMAL endothelia.

[Happylady]

I forgot to add that the latest info on this is that all those hydrogels we used to think were safe are actually damaging the endothelial cells, slowly, inexoribly, year after year. They actually morph into freak cells that can't pump water out of the cornea. And this is happening to previously NORMAL endothelia.

Tell me more about this. Can you provide any links?

[drk]

My thinking on the differences between the silicone hydrogels:

Acuvue family: Oasys = Advance, but better. These have the softest, most "normal" feel, and have great oxygen transmission. Best for most people.

Ciba's and B&L's are too similar to differentiate, IMO. These are stiffer, which is an absolute negative. They do, however, have a surface treatment, which is a superior way of making the lens wet. These have low amounts of water, so they would have the least dehydration. Best for depositors or dry eye patients.

Cooper's lens pre-approval: sounds like Acuvue's concept.

Hydrogels are not obsolete, yet, and may never be, but I think that these lenses will get 75% market share w/i 5 years.

[William Stacy O.D.]

Tell me more about this. Can you provide any links?

Nope. Just a meeting I went to about 2 months ago, with a presentation (with lots of specular photography of endothelial cells gone bad) by a UC Berkelely optometry professor. Couldn't even give you his name, as I just absorb this stuff, sorry, I don't document it...

[Skagen]

My thinking on the differences between the silicone hydrogels:

Acuvue family: Oasys = Advance, but better. These have the softest, most "normal" feel, and have great oxygen transmission. Best for most people.

Ciba's and B&L's are too similar to differentiate, IMO. These are stiffer, which is an absolute negative. They do, however, have a surface treatment, which is a superior way of making the lens wet. These have low amounts of water, so they would have the least dehydration. Best for depositors or dry eye patients.

Cooper's lens pre-approval: sounds like Acuvue's concept.

Hydrogels are not obsolete, yet, and may never be, but I think that these lenses will get 75% market share w/i 5 years.

From the details I got, Accuvue Advance is actually lower in Oxgen transmission levels than Cibas Night & Day, Ciba's 02 Optix and the B&L Hydrogel. It is the lowest of all four.

I found it to be very comfortable to wear, but had a major issue with "halo" effect in low light and computer. The Night & Day for me was slight less comfortable (but still okay) except with long computer usage, where it consistently gave me irritating sensation. I haven't tried the other two.

But the couple data points I have so far leave me wondering if there is some tradeoff of Oxygen transmissibility for comfort - or at least percived comfort.

Nope. Just a meeting I went to about 2 months ago, with a presentation (with lots of specular photography of endothelial cells gone bad) by a UC Berkelely optometry professor. Couldn't even give you his name, as I just absorb this stuff, sorry, I don't document it...

I would ditto and say that I'd love to hear more if you can trawl up any details at any point.

[SpecialT]

But the couple data points I have so far leave me wondering if there is some tradeoff of Oxygen transmissibility for comfort - or at least percived comfort.

This is not necessarily true. It is the stiffness of some of these higher oxygen lenses that causes comfort issues. Lenses like the Oasis are the best of both worlds, great comfort and high oxygen transmissability. Actually, high oxygen lenses can improve end of day comfort. In the future you will likely see attention given to the stiffness of the high O2 lenses. But even now, I recommend them almost always.

[QDO1]

the prescriber is responsible for the lens specification supplied, and he makes those decisions based on the condition, measurements and prescription of your eyes. As the patient you are responsible for following his decisions about wearing times, and cleaning routines, and comming back for checks on time.

Without sounding rude, you want to try remaining a patient, and not becoming a consumer. There are a whole range of issues, besides oxygen permeability, that can effect your ocular health. Your practitioner will be aware of the bigger picture, but he probrably will simpley distil those many thought processes down to a choice of 2 lenses

Price, or one lens parameter ought not to be the reason for taking route A or Route B. Trust your Optician, who will be highly trained to take those decisions for you, and ensure you follow the directions he gives you regarding check upps, lens and cleaning soloution usage

[HarryChiling]

Skagen a great resource for contact lens information is http://www.clspectrum.com this site is very informative and geared towards the eyecare professional. Ultimately let your doctor help you make a decision regarding the correct lens option for you, don't attack him/her with all the information you pick up.

Everyone keeps on hollering about higher oxygen permeability, however the silicone hydrogel lenses have the hydrogel component in them to allow for the transport of fluids and ions wich is very important as well. In order to increase the oxygen permeability you decrease the transmitability of the fluids and ions. A minimum sodium ion and hydraulic permiability of 0.2 * 10-6 cm^2 sec^-1 is required for lens movement (Tighe 2000). Their must be a balance between oxygen permeability and hydraulic flow or the lenses bind. The contact lenses created today are using surface treatments to help with the hydraulic flow allowing them to manipulate these variables seprately so you can have a high oxygen permeability and a high water and ion transmitability.

Some articles you may find of interest to you are:

http://www.clspectrum.com/article.as...er\0996006.htm

http://www.clspectrum.com/article.as...ry\0102038.htm

http://www.clspectrum.com/article.as...con\080205.htm

and if you do a simple search at the site for oxygen permeability then you will pull up lots of relevant information.

[chip anderson]

I don't know how many patients I have had over the years reject lenses because the lacked "stiffness". Some patients flatly refuse B&L hydrogels because, while they fit and feel well they are too difficult to handle and are prone to "stick to themselves."
In some cases "stiffness makes the lens center better and may mask minicule amounts of residual cylinder.
In the case of rigid lenses, I have seen many patients who could only see 20/80 while if the lids were manually held open, 20/20 was possible. Why: Because the lab was trying to impress us with how thin they could be made.
Many older patients with poor vision and limited manual dexterity and reduced sensation in the fingers from diabetes and the like will break flanges off rigid lenses (occasionally not noticing this due to poor digital sensitivity and insert the broken lens.)
The rediculously thin Plus PMMA lenses described by Soper and Girard were prone to chip on the edged. So was the lens that looked best on the eye best for the patient? No.

My point: You have to fit the whole patient, not just looks good to the whiz kid in the marketing department.

[drk]

[QUOTE=Skagen]From the details I got, Accuvue Advance is actually lower in Oxgen transmission levels than Cibas Night & Day, Ciba's 02 Optix and the B&L Hydrogel. It is the lowest of all four.

But the couple data points I have so far leave me wondering if there is some tradeoff of Oxygen transmissibility for comfort - or at least percived comfort.
QUOTE]

Point #1: there is a "diminishing returns" effect going on, I believe. The transmission numbers could go all the way to "100%", but the corneal health is not necessarily going to improve linearly. I'm of the opinion that the Advance transmission numbers for daily wear, at least, are well-sufficient, and additional is less beneficial than perceived.

Point #2: Historically, there have been, unfortunately, many trade-offs between transmission and other desirable qualities, such as comfort, but that's not necessarily fixed in stone. These newer lenses are trying to achieve the best of both worlds, and I think they're coming close.

[SpecialT]

I don't know how many patients I have had over the years reject lenses because the lacked "stiffness". Some patients flatly refuse B&L hydrogels because, while they fit and feel well they are too difficult to handle and are prone to "stick to themselves."
In some cases "stiffness makes the lens center better and may mask minicule amounts of residual cylinder.

I couldn't agree more. I also think that as "second generation" silicone hydrogel lenses begin to emerge (like the oasis), a great middle point will be reached. I also think that it is interesting that one of the softer hydrogels (the advance) is the only large diameter toric (14.5). The purevision is toric is a 14.0 diameter and makes me wonder about comfort just outside the limbus with larger diameters in the newer materials. We will just have to see when more silicone hydrogel torics are available.

[Skagen]

HarryChiling - thanks for the info and links. Unfortunately the links dont seem to work for me. I get a dead link. Not sure why...

Nope. Just a meeting I went to about 2 months ago, with a presentation (with lots of specular photography of endothelial cells gone bad) by a UC Berkelely optometry professor. Couldn't even give you his name, as I just absorb this stuff, sorry, I don't document it...

Is this the study that you were referring to, but could not remember?
http://optometry.berkeley.edu/class/...4_Fleiszig.pdf

Without sounding rude, you want to try remaining a patient, and not becoming a consumer.

I don't think its any different from a person with a lawyer. You're not going to make all the calls, but you better be aware of what is going on. In any case I'm not "interfering" with anything - the guy says my eyes are completely healthy and he is willing to prescribe any of these as long I feel comfortable in them - so this is the sitation. Its not like I'm telling him what to prescribe. I'm trying to understand the implications of the choices he is giving me.

[William Stacy O.D.]

Is this the study that you were referring to, but could not remember?
http://optometry.berkeley.edu/class/...4_Fleiszig.pdf

no


That's a nice generic talk on CL problems, but not the one I was thinking of, which was pretty much a scathing attack on fitting any old hydrogels because of the long term endo damage...

[QDO1]

I don't think its any different from a person with a lawyer. You're not going to make all the calls, but you better be aware of what is going on. In any case I'm not "interfering" with anything - the guy says my eyes are completely healthy and he is willing to prescribe any of these as long I feel comfortable in them - so this is the sitation. Its not like I'm telling him what to prescribe. I'm trying to understand the implications of the choices he is giving me.

thats the best sort of patient in my books. there is another sort, who then goes down the library, and gets hung up on 1 strand of 1 idea and blows that out of all proportion, whilst ignoring the most important info.