Silicone hydrogel lenses

[James Colclough]

Hi, does anyone out there currently piggyback with these.

I am using biomedics daylies, as Kingston charge for these I thought I might look into Silicone hydrogel lenses, as they are meant to breathe

[Ryan Smith Canada]

I am new to this forum(this post is as far as I have read) and I do piggyback and am happy most of the time(everyone here seems to know about the "bad contact days") It seems I am a bit strange in how I wear mine and I was expacting to see in this group others that wear their lenses like I do.... For about 5-6 years I wore only RGP lens and only took them out to clean or put new ones in couple times a year, yes I did sleep in them always and in the morning they were foggy and had some white c**p but in a few min. and with some attention they are fine again. I found more comfort to leave them in becouse any time I used solution they would float around for a while. I sometimes went weeks without taking them out to clean unless I felt some dirt or something(of course windy or dusty days are horrable and they would come out many times a day). My optometrist of course did not like this extended wear and examined me regularly and never found any signs or corneal wear or any problems. With comfort being an issue I decided to try the hybrids(synergeyes) and they seemed o.k. I had trouble removing them and we weren't completly happy with the fit so we gave "piggybacking" a try and it worked well imediatly. I only planned to piggyback on days or when doing things that comfort was an issue(golfing in wind, motorcycle,dusty days or dusty environments,lawn mowing, or just bad contact days), soon realised that the silicone hyrogel "avuvue oasys by Johnson + Johnson" are high oxygen permable and they say that 6 day and night is o.k. . I sleep 7 nights a week and replace the silicone hydrogel every sunday night . This has been my routine for close to 1 1/2 years with few problems although sometimes I feel the need to take both contacts out of one eye overnight or for a whole day. I could not imagine taking all my contacts out every night as my vision so poor without at least one eye in that I struggle to get them back in and all my comfort issue seem to come from the install/remove process. I don't know how this happens but somtimes the soft lens will come out and leave the RGP in place perfectly and if I don't notice the soft lens on my cheek or shirt I have a problem because I later take out the RGP (without the RGP poor vision) and then spend some time focused on removing a soft lens that isn't there.That is stressful and painfull. Long winded story and I know my extended wear style is not recomended , but is seems to work great for me .So.. Yes the silicon hyrogels are good for piggybacking and is any else tried or using the extended wear route I would love to hear from you.

[rosemary johnson]

WoW!! that's some extended wear.
Well, if it works ..... congratulationso n finding somethign so satisfactory.
I'f een piggy backing for a while, and some of the soft lenses I've used are the J&J Acuvue - daily disposables, allegedly though i guess not in your case!
Never tried leaving them in half so long as you though! - sometimes come home form work and lie down for a quick nap and wake up 3 hours later with the lenses still in and feeling a bit gummy - but now in the days of RGP materials that wears off fairly quickly.
But I'm piggybacking with sclerals - I guess yours are the smaller corneallenses (8mm dianter rather than 24mm).
As regards the problems with putting lenses in and taking them out - I wonder if you are reacting badly to something in the solutions? - maybe a preservative. Have you tried experimenting with lots of different types?
Welcome to the forums, BTW!
Rosemary

[Lynn White]

OK... As a professional I have to give a health warning to Ryan's post - please do NOT try this yourselves without first checking with your own professional. This type of wearing pattern is something no-one would really be happy with in even a normal eye, never mind one compromised by keratoconus! That's why, Ryan, you did not find anyone here doing the same as you!

Why can it be a problem, you may ask? Well, the eye needs oxygen to maintain its health and it derives this directly from the atmosphere. When you sleep, you eyes are obviously closed and oxygen is taken from the capillaries in your lids. When you wear a lens overnight, you are putting a barrier between your cornea and the inside of your lid, so to get enough oxygen to the eye, the lens needs to be of a type which will easily transmit oxygen and Silicone Hydrogel lenses are the best type of lens for this.

So what happens if your eye does not get enough oxygen?

Well, in a desperate attempt to get at oxygen dissolved in your tears, the cornea starts to absorb fluid from your tears and starts to become waterlogged. This in itself causes pressure on your nerve endings which causes a form of anaesthesia which has the unfortunate effect of making everything seem nice and comfortable. I say unfortunate because this leads patients to think everything is hunky dory. It also leads to fogging of your vision, which is why, Ryan, you sometimes wake up with fogginess (it not all due to stuff on your lenses).

The eye does recover rapidly once your eye opens and with an RGP, the oxygen can get in round the edges of the lens - but if you are piggybacking then this takes much longer to happen as it has to get through the soft lens. When you do take your lenses out, the oxygen rushes in rapidly to replenish supplies and usually sensitivity comes back with a vengeance, hence the comfort issues Ryan talked about. Again, this tends to lead the patietn to wear the lenses more and remove less in the mistaken belief that the eyes are "better" with lenses in.

Long term, the constant oxygen deprivation can lead to damage in the back layer of your cornea, the endothelium. It is this layer that is responsible for maintaining the water content of your cornea and when its damaged, the cells coalesce and drop in number. The result can range from instability of prescription to full blown breakdown in function leading to opacity. Before this happens though, it is not uncommon for blood vessels to start growing into the cornea and once this happens, it reduces the chance of being able to have a corneal graft successfully if needed.

It is indeed ALL of these possibilities that has deterred many practitioners from fitting soft lenses of any type for keratoconus - and that is wearing them on a take out at the end of the day basis! Now that soft lenses for KC are available in Silicone Hydrogel, these issues have been resolved but even so, no-one would dream of doing this on an overnight wear basis for long term use.

Ryan, your practitioner is monitoring you for all these problems I mentioned and I know it is hard to justify taking you off this system when you seem to be doing OK with it. However, any practitioner who deals with complicated fittings can give you details of patients this has happened to and many of them were "OK for years". Frankly its not worth the risk to ocular health.

Lynn

[colonial]

Hallo Lynn, I am glad to have seen your Post here. You have discribed the processes that can derive with Keratoconus and lens wearing, in a way, that i have been able to understand well.
I hope you don't mind me telling you "my" story quickly?

I myself have had cornea drafts done on both eyes for around ten years now. During this time i have corrected sight with either glases or soft lenses.
As the needed correction values have become more and more critical to achieve (eg. +5.5 -8.0 115/ Left eye), I have gone to have conditions checked by a doctor here in Switzerland.
On this visit, I was dissapointed to hear that my drafts will not even last for another 10 years. (1997 i was told by the doctor surgeon ,this would be a lifetime fix). And unfortunately I did not get much else info, (he was talking about something you described above though), except that the only thing he could recommend is to have the "crosslinking" (to stabilise the cornea) treatment done in the mean time.
To keep things short, I am left neither here nor there,
I should probably stop wearing soft lenses? and only use glasses although vision is less good?
Are the rigid lenses okay to use ?(although as i remember, where a bit uncomfortable, because of the scar of the draft)
I not really optimistic about having this treatment done, could this help ?

Marc

[Anne Klepacz]

Hello Marc and welcome to the forum!
I'm sure Lynn will be able to give you a more scientific answer than I can, but I really wonder why you were told that your grafts would not last. Both my eyes were grafted more than 20 years ago, and the grafts are still going strong. And we have members with grafts 30-40 years old! I also wonder why you were told that you should have crosslinking to stabilise your corneas. A graft does precisely that, so unless KC comes back post-graft (which is possible, but VERY rare) I can't see what benefit crosslinking would be. But I'm ready to be corrected on that if others have more information and of course there may be particular factors affecting your grafts that have led to this advice.
As for lenses, I (along with many other people here) have worn rigid (rgp) corneal lenses ever since my grafts, so that is certainly an option.
Anne

[Andrew MacLean]

Marc

Welcome to the forum!

Quite a lot of us, post graft, are wearing hard lenses of one sort or another. I guess that Sclerals and RGP corneals are used as frequently post surgery as they are before.

I share Anne's questions about the point of CXL after a graft, although like Anne I am willing to be told that it is a good thing, so long as I get an explanation of why

All the best

Andrew

[colonial]

Hallo Anne and Andrew,
Thanks for giving me a bigger picture on graft lifetime. I was relieved just to read that.
I must admit I'm really not updated on all the knowledge and development with Keratoconus.
I was glad i got those 2 Operations behind me 1997/98 and I haven't been to much concerned about it since.
I was lucky my sight was good post, even though I often have had to get Lenses/glasses refitted, due to change of sight.
Changes sort of every 6 months to 1 year, have you also experienced this?

Marc

[Andrew MacLean]

Actually, I guess that post graft we should anticipate the same sort of trajectory of change as might have been normal in healthy eyes. As we get older, vision changes.

All the best

Andrew

[Lynn White]

Hi Marc

The problem with commenting on what you were told by someone in a consultation is that what you recall is often out of context. Plus, it is incredibly hard to remember all that you are being told!

While I would agree in general with Anne and Andrew about the length of time grafts can last, it does sound possible that you have some other issues such as vascularisation and/or problems with progressing KC despite grafting. The fact you need constant changes of prescription may indicate some changes here. It would not be ususal to suggest CXL on grafts unless there was a perceived need.

However, no-one here can possibly work out what you were told and what I just said may really be way off the mark! I do suggest you contact your consultant's secretary and ask that you be sent a letter explaining the outcome of your last visit, then you at least know what was actually said.

Lynn