Twisting the KC way!

[Sajeev]

I was reading on the net (can't remember where) that it is possible to rotate/twist you cornea surgically, so that an uneffected part of your cornea can be postioned to cover the pupil... the area needed is just 5mm for the pupil to see from...

It will not work for everyone i don't think... but you keep you own cornea... and the benfits that gives... like in not needing to have doner tissue or in theory having zero chance of rejection episodes and keeping your own endothilum cells ect

Its little simple innovations like this which mean a lot to us i think, done by those few doctors, who will "think out of the box"

[John Smith]

That's really interesting. For most of us the apex of the cone is below the centre of the pupil. (it was referred to at our last conference as the "saggy bosom" effect)

I wonder though whether that effect is because of gravity, and whether the rotated cornea will eventually sag downwards again?

Also, I suppose that the surface which may have been difficult to fit with a lens would still be difficult to fit (although not requiring such a strong lens maybe).

I suspect that many surgeons (and patients?) will feel that if they're going to go through an operation which removes the cornea, they may as well have one in which they receive a KC-free cornea!

[Sajeev]

Big saggy cones will still be big and saggy after its been rotated, so the problems that causes will still be a problem, so not all KC corneas are suitable for this method.

This method is mostly used when there is scarring in the field of view which only needs to be moved out of the way... the results are comparable to a PK graft, and this method can be used where donar tissue is hard to come by, like for instance in countries where donering don't happen due to religious, or cultural reasons. Also this method does not stop the person having a PK graft if this method does not work for them, ...not sure of a dalk though...

[Michael P]

This is very interesting Sajeev.

I have no idea about how saggy my corneas are ( I suspect not that saggy ) but vision in my right eye is poor and can't be improved because of the scarring.

I am going to Moorfields on 12 September and I will try to remember to ask about this.

[jayuk]

Whilst good in theory, in reality its more than likely to be a reality in mickey mouse land...as any kind of change or "twist" will cause the surface area of the cornea, regardless of 5mm or 2mm, to further thin...and thus cause an increase in perforating the already thin area of the cornea...regardless if its the "saggy" part or not....with the introduction of the DALK....theres probably no milage in pursuing this from a Professional Perspective as the rejection rates are severely depressed...., you keep your own endothelial cells, and overall you can achieve a 6/9 corrective VA over the 6-18 month recovery period.

[Sajeev]

Please do ask Micheal, ask the consultant if possible, hopfully they will think about it for a while before answering and not give a knee jerk reaction. They should find it in the literature.

Apparently what they do is bring clear cornea in to the field off view by rotating the cornea at a point 5mm away from the center of the cornea, so that to bring 5mm of "new" clear cornea over your pupil.

Its much easier to explain with a pencil and paper.

Anyway, with this method alot of the steps that are required for a PK graft is not needed, its just a matter of rotating the cornea.

All the best

[Sajeev]

It really does happen, and you got the whole thing wrong in the way its done, you are presuming much Jay?!

[jayuk]

Ahh ok..."rotate / twist"....maybe you used incorrect terms?....or I didnt understand..probably the latter!

If its surgically assisted, it cutting and re-attachment than it will more than likely use 90% of the procedure of a PK et al....so im not really following you....

do enlighten...as Im always keen to learn..

a) where would the clear cornea come from?..another part of the surface which doesnt cover the central area?

b) if this is cut out?....than what happens in its place?

c) if b doesnt apply...than how is it twisted or rotated ?

[Sajeev]

I'll try to write using as fewer words as possible as then the words will not then run in to each other.

a) yes that is right, the "bad" side of your cornea button is postioned away from your field of view

b) your own cornea goes back at another postion with the clear side of the doner button over your field of view.

The process was called something which generally anyone would pass it by if they read it, i'll try to find it again if possible, its just another option being done, its like "recycling" your own cornea.

[jayuk]

Hmm so thats two cuts and two sets of sutures?...if so thats far to barbaric to the corneal surface....wouldnt you agree?..although maybe barbaric is an immature word...lets say...far too traumatic to the eye?

If the above stands true, than to me, that sounds like much more work than a PK....and a longer recovery time also.......wouldnt you agree?....and the fact that we have DALKs now..it just seems a no-brainer to choose a DALK than a potential like the above?......