recent study - reject refractive surgery candidates and KC
Posted: Fri 06 May 2005 10:58 pm
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!!)
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!!)