Does contact lens use accelrate KC?

[jayuk]

Hari

I see that you had that luxury of having that decision not to use your lenses for 12 months; which would make me assume that your vision was not that bad?....I am sure many couldnt do that, as I remember without my lenses I couldnt see my hand unless it was about 3 inches from my face.......all i could see was a blob......but as you say....you made the decision and havent looked back...

Can i ask what your vision was before Mini Ark?...with lenses and without lenses? and what it is now Post Mini Ark?

J

[Anne B]

I asked the question about scarring because apparently i have no scarring.
I also have never worn contact lenses for any longer than a couple of weeks.
This has always interesred me!

I'm probaly way off track here but just thought i would mention this

[Hari Navarro]

As the previous study suggests it is not only 'incorrect' lens fitting that causes scarring. Corneal warpage is not an uncommon event... just read any pre Lasik instruction... they clearly state that you should remove your lenses some time before surgury... so that your cornea has time to return to its normal shape!
Lens induced scarring and oxygen transmission reduction are well documented (although some say that this effect is minimal and is far outweighed by the possitive effect of being able to see... easy to say if it is not your cornea being distorted).
The issue here is that contact lenses give many of us the chance to operate in society, they mask the problem of KC and replace it with an 'acceptable' alternative. To me this trade off was far from acceptable.
Break-through lens technology speaks of all kinds of fantastic designs... but I am yet to be convinced that placing ANY foreign object against my cornea is in anyway healthy.

Hari

[Hari Navarro]

I am do not have my recent files with me at the moment (moving house ) but these were my early readings:

Name: Hari Navarro
Nationality: New Zealander

Stage of KC at initial A.R.K. visit:
OS: II OD: III

Age: 37 Keratoconus: bilateral
Year diagnosed: 1999
Date of operation: 09/11/04

[Initial results] - pre/post A.R.K.

Keratometric values: Keratometric values:
OS: pre 47,4 / 48,84 post 42 / 44
OD: pre 57,4 / 57,69 post 43,15 / 43,60

Astigmatism diopters:
OS: pre 3,25 post +1,50
OD: pre 3 25 post +0,50

Corneal thickness: Corneal thickness:
OS: pre 440 post 460
OD: pre 440 post 440

Sorry this is far less than complete but its all I have here at the moment.
I am very over due for a check up I will post all my updated data when I recieve it.
My eyesight was extremely poor for the year I took to relax my eyes and find an alternative, but it is one that I am very glad I took.

Anne you are not off course as it is not solely contact lenses that cause scarring... but to my mind they surely do not help,

Hari

[jayuk]

blimey, your K readings have gone down a fair bit as has the Astigmatism!....although its interesting to see that the corneal thickness didnt change too much..which kinda shows that the scarring caused by the incisions would probably be minimal as far as tissue buildup is concerned!

What do you see now?...as in without glasses/ Can you for example read a newspaper?

[Hari Navarro]

At present I live totally uncorrected... I read, drive and watch TV without any form of lens.
But my eyesight is not 100% there are times, especially on hot days, when I have a slight blurring. I expect my operation to heal to an extent and then settle... the surgical trick in ARK's case is not to overcorrect.

As far as the thickness readings these were taken only a few months following my operation... I'm very interested to see what they will be on my next visit.

[Andrew MacLean]

I think that somewhere on the site there is an excellent article by Ken Pullam that addresses the issues in this string.

I'd like to see comparative data on Sclerals as opposed to corneal RGP lenses or even sogt or soft skirted lenses.

Andrew

[jayuk]

Andrew

I hear what you are saying!...I once asked Ken about the effects of Sclerals on KC and if they aided in hydrops being formed.....as in my wisdom (or when I was bored once) I noticed that when the sclerals went into the eye, the cornea/front of the eye had a mild suction effect...which basically helps the water/saline stay in place. Now if you have medium/advance KC and you are causing a greater amount of suction pushing the cone forward...does that not affect / aid in the creation of Hydrops?........There was No evidence to suggest this I was told. But on the other side of the coin I have heard of other opticians share this same opinion.....

J

[Hari Navarro]

I have never met Ken Pullum but by reputation I hear that he is very good at what he does and has a keen interest in his work.
But in saying that, and in reference to the article that Andrew refers to, I think that having a contact lens specialist comment on a treatment that contridicts lens wear is far from objective.
Also the articles heading instantly taints the readers perception before we even have chance to get to the body of the article: A cure for keratoconus? excercise caution!

Any minor problems with the mechanical actions of rigid contact lenses on the cornea pale into insignificance when compared to anything caused by surgery, including RK.

Mr Pullum begins by rendering all mechanical contact lens related action toward the cornea as insignificant... and he again states the age old lens fitters comeback that compared with the alternative treatments lenses are relatively non envasive??'

I do not say that lenses are the sole cause of scarring... but then scarring is only part of the negative aspect of lens wear. Oxygen transmission is another... the cornea is the only part of the human body that draws oxygen directly from outside of the body. Lens manufacturers will claim endlessly to have developed the perfect artifical product that allows the free flow of oxygen to the ocular surface... but what exactly, in terms of optimum flow does the cornea consider adiquate? I mean whos to say exactly what the cornea needs to operate, especially one already compromissed by keratoconus. Yes there are studys and reports but how do these relate exactly in practical terms... I do not dismiss them but there are always many sides to a reports acceptence. The fact that any positive report pumps up the huge contact lens industry should not be dismmised either.
The human cornea was never designed to operate through a barrier of any kind.
Again Mr. Pullum assures us with the same arguement:

The great visual advantages of contact lens wear in KC easily outweigh the minor reduction in corneal metabolic activity.

There is no evidence that contact lenses act as a suction pump, with the implication that this makes the cornea more distended.

See the following article:
http://www.aao.org/education/sit_cornea/0018.cfm

The authors have proposed that a “push-pullâ€Â

[Hari Navarro]

Further reports:
The effects of long-term contact lens wear on corneal thickness, curvature, and surface regularity.
Conclusions:

Long-term contact lens wear appears to decrease the entire corneal thickness and increase the corneal curvature and surface irregularity.
http://linkinghub.elsevier.com/retrieve/pii/S0161642099000275

Topographic changes in contact lens-induced corneal warpage.
A much longer time without contact lenses than had been previously reported, up to 5 months, was required for a return of a stable corneal topography in eyes with contact lens-induced corneal warpage caused by rigid lenses.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=90326351&dopt=Citation

Development of keratoconus after contact lens wear. Patient characteristics

We believe that these patients suggest that long-term contact lens wear is a factor that can lead to keratoconus.

http://archopht.ama-assn.org/cgi/content/abstract/108/4/534

If you look hard enough you will find just as many reports that refute what I have highlighted above.
But at the end of the day the question has to be asked - Exactly what damage if any are we causing to our cornea's... and also, are we being given the best possible treatment or are contacts really nothing more than a crutch to allow us to function through the day?
If there is any truth at all to my last comment then I find it extremely hard to understand how a treatment 'possibility' such as mini ARK can so easily be brushed aside.
Surely if we are in this position of 'masking' but not treating our keratoconus then every avenue should be sought.

Hari