Orthokeratology

[yiannisl]

Hi,

I recently came across Orthokeratology, the temporary, re-shaping of the cornea, by application of pressure overnight. This pressure is applied by the use of contact lenses, which are safe (FDA approved) to wear while asleep.

Questions is, does anyone know about the general safety of this method and also its appropriateness and effectiveness in the case of KC?

The primary cases that are discussed in most OrthoK lenses sites refer to myopia and mild astigmatism...

Thanks a lot
Yiannis

[jayuk]

Yiannis

Welcome to the forum!

This particular treatment works well, allegedly, with those that have mild astigmatism....however the potential downfall of this is the total amount of time the cornea "holds" itself before returning to its original........some say that you can achieve 12-15 hours...whilst real world results seem to show less........I beleive its all down to how much astigmatism the cornea has..

I have not heard any KC patients use this procedure.....but I am sure it would be interesting to find out

Hope that helps

J

[Andrew MacLean]

yiannisl

Welcome to the forum

Interestingly enough we were hopeing that the next speaker at the Scottish Support Group would talk about Orthokeratology, although so far as I am aware it has not been offered to patients with KC.

I read an article on the internet about it some time ago, while I was still wearinglenses, and asked my own optometrist. She had seen the same article as I had read when it appeared in a journal, but was not keen on advocating the tecnique as a management strategy for KC.

Andrew

[Knight]

orthok doesn't pose any more risk than regular contact lens wearing in general. Althou, it took me a while to find this again but ...

...overnight orthokeratology appears to be safe and effective .... an interesting side ... circular or arc-shaped deposition, presumed to be iron deposition in the basal layer of the corneal epithelium, has been noted in several cases of patients undergoing treatment with overnight wear of reverse geometry lenses ...

SOURCE
As you already stated its main use if for myopia and mild astigmatism, so its not generally offered to KC patients because the cornea can be so steep. There have been some improvements since I last read about this a few years back with better topographical mapping these days, althou I view orthok as more of a convenience, I don't imagine it would be any more comfortable to wear an RG lens press fitting over an advanced KC cornea than for example a scleral contact lens.
Even some of the maps I have seen, those comparing pre-post treatment, the original isn't nearly as bad as a KC cornea, so I'd doubt if it is even possible as far as KC is related because things can change so rapidly, to my thinking ... your eyes move a lot as you know during, mild-sleep to REM sleep, so as far as KC is concerned it's not unlikely you could be wearing an ill-fitting lens and not know it right away causing localized blanching even scaring while you sleep, just the same as normal RPG contacts...

[ChrisJ]

Hi

My optometrist has been telling me about the development of orthokeratology for keratoconus for the last couple of years, and recently told me that it could be available for KC patients within a couple of years. I remember him saying that it may be possible that after a few years of ortho-k, lenses would only have to be worn 1 night per week to achieve good vision for the rest of the week.

Hope this helps

[jayuk]

Chris J.....

I would highly doubt this.......the reason why I say this is because Lens Wear will NOT stop the progress of KC....this was an old wives tale..which, surprisingly, alot of opticians still think is the case potentially!

A KC affected cornea needs to have a contact lens which sits comfortably on the cornea and requires a number of visits. Any heavy bearing on the cornea will have a negative impact on the structure of the tissue and thus I would highly doubt this technique will be of use to those with mild/moderate KC..........

I can see its use on mild Astigmatism but def not in KC....unless of course there is another element to the treatment which allows the cornea to become malleable

J

[Andrew MacLean]

We hope to have the head of the department of Optometry at GCU at the next Scottish Group meeting.

We'll ask him about othokeratology. Like Jay I cannot see how this procedure alone can deliver the sorts of result that Chris J was promised.

Even in mild astigmatism orthokeratology seems to remain a controversial technique.

Andrew

[yiannisl]

Thank you all for taking the time to read my post and reply to it, much appreciated. Shame to hear that OrthoK is debatable. It sounded as a temporary solution but still a good one...

My main interest in it was mostly because I just can't get used to gas-permeable lenses and therefore use nothing to improve my sight...

This is probably a long shot but I had also heard about a "permanent" lens they were working on, which was based on a gel-like material that they fitted onto the cornea. I'm not sure how that would work with changing topography etc. but I was wondering if anyone had heard anything about this

Thanks
Yiannis

[jayuk]

Yiannies

Implantable lenses have been about for around 2 years in one shape or another. There use is generaly for those with mild/mod astigmatism; however it would be interesting to see any there were any out there for KC!

Jay

[Andrew MacLean]

yiannisl

Or there are techniques like Intacs (already available on the NHS and becoming more common), or even cross linking (C3R is now clearing ethics committees and will soon be very common in the UK). don't give up

Andrew