recent study - reject refractive surgery candidates and KC

[Lynn White]

Hi all...

I know I have been chuntering on about subclinical KC being picked up by refractive surgery corneal topography... so I did a net search and found this study... I can't publish the full thing here as its a pay online article - but anyone wanting a pdf file can email me for one.

Basically a study was done of the topgraphy mappings of 200 corneas rejected for corneal surgery.

70 out of the 200 were rejected for the following reasons...

Lower steep pattern 43

irregular astigmatism 7

decentred 3

KC suspect 11

prob KC 6

Now... considering that keratoconics have a lower steep pattern and irregular astigmatism and decentred apices... it seems pretty much that those supposedly non KC corneas are very much KC like... food for thought eh??

It has long been my thought that corneas like the "lower steep pattern" are KC waiting to happen...a trigger like stress, childbirth, severe eye rubbing etc etc... could change a potential KC into a progressive one...

Just doing the numbers... the confirmed KC eyes in this study were 16%.

If you count all of the rejected eyes as being KC like (bearing in mind there were 32 "upper steep corneae" - none of which were rejected for surgery - the table I listed above was only for those actually rejected)

then you are talking 35% of eyes presenting for refractive surgery are rejected because they have KC suspect corneas...

That is an AWFUL lot of corneas!! I suppose that really boils down to about 17% of people presenting for surgery if you divide it by 2. Seeing as glaucoma is rated as a serious disease as it affects 2% of adults over 40... I do rather think that KC is rather more prevalent that previously thought.

Obviously... this does not represent the total number of people in the population.. only those going for surgery... but still....

Very much food for thought!

Lynn

Here is the link: article

(re-edited so it doesn't take up so much room!!)

[steveg]

Lynn,
I was officially diagnosed with KC in the mid-70s, wore (struggled) with the large hard lenses for years, until having grafts in 92&95. I have had no problems with the grafts.

I was very curious when it was diagnosed as to why I had got this condition. No family history etc. It was suggested to me at the time it could have been linked to measles, I did have measles as a small child. I was also aware even before my KC was diagnosed that something was not quite right with my sight, and that things like streetlights has this (slight) flaring effect. Over the years the condition did worsen. Obviously KC was with me before it was diagnosed, and I have always wondered about the measles connection.

If there is a connection, it would not surprise that a lot more people have KC, even if it is very mild, and does not cause them any bother. Going of your figures, it would seem that it is more common than thought.

Steve

[Susan Mason]

All

Me too, sounds familiar.

I was ok until AFTER childbirth then things started to go with my eyesight. At first it took a long time to have it confirmed, over 3 years in fact however, during all that time I really struggled and worried an awful lot.

Once diagnosed whilst it was a shock, then started the bumpy ride to what to do to see ok and how to live through periods of no useful sight.

Pretty rubbish really, and at the end of the day whilst I know it could be worse it is bad enough for me and any comments are useful as it allows us to look at matters from another angle or reasearch options that maybe we were not aware of.

So far I have missed too much of my childs life and I certainly don't intend this to continue if I can find a way to see better. Especially, if it does not involve major surgery that whilst may well be necessary in some cases once done is done and after all what suits one will not suit all..

Susan

[Sajeev]

Just to add what has been said in the last two posts....I was told by one opom' that there is a trail of thought that suggests KC are "spots" you get in your cornea like the spots you get on your face as a teenager...I guess its just another theory!


Just something else that jogged my recall in what Susan said...some treatments are reversable the Artisan Implants have the benifit of being completely reversable/changable if need be....it is new, new for KC...

Its got the added benfit in that people who had a corneal transplant can have it as in my friends case who just had the implant done under his graft...just some good news i wanted to pass on...

This development is something to follow with interest i think and hopfully more people can benifit...

Going back to KC being more common than previously thought...it has been documented on PUB-MED (the web-site with a lot of studies)
Just type in "keratoconus" in the search field on the site to see all the listed studies...and its FREE!

Or there is a topic opened about this a long time ago which highlights this at http://www.kcfreedom.org

Warmest Regards

[Lynn White]

Having been through the full article more throroughly, the implication is that people with sub-clinical KC may "self select" for surgery more than people who have normal eyes because they do not get on well with glasses. The number of KC-like corneas in the group looked at, is way above national averages... though this does presuppose that "national averages" are correct.

The other interesting fact is that the "lower steep" topographic maps (ie those that were similar to KC but not actually KC) were used as a basis to reject patients simply because the surgeons were not really sure what to do with them! It is known that these cases can go on to develop KC after laser surgery, so its a case of better safe than sorry.

What is needed is a study whereby such corneas are monitored over a period of years to see if any traumas or illnesses (such as measles, which is known to precipitate squints) do in fact trigger KC. These sort of things are very long term though and its funding it which can be difficult! However, I am willing to bet that some American clinics that do a lot of laser surgery are seriously thinking of doing this as in the long run, its cheaper than being sued for causing KC!

Lynn