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Graft size and lifespan of graft

Posted: Sat 23 Dec 2006 1:35 am
by Vic
After having been under the care of Bristol Eye Hospital for 7 years, I transferred to Moorfields and had my first appt there this week. For a while I had started to be slightly doubtful of some of the things that I had been told in Bristol, and in some ways the appt this week confirmed that. Bristol had written off my right eye as not correctable with lenses as I found them difficult the first time I had the lenses put in, whereas the optom at Moorfields (and Louise, who kindly came with me) both reassured me that this is a perfectly normal reaction and does not mean lens intolerance in the slightest. Within 20 minutes the optom had managed to get a decent fit and said that the KC in my right eye was fairly mild, which was reassuring as I’d never been told this before.

I had a graft in my left eye in Bristol 5 years ago (which again in retrospect looking back, there is every possibility that this was done prematurely, and having read others’ accounts of their experiences at the BEH since then, it does seem that they are a little hasty sometimes in going for the surgical option). However what concerned me about the appt this week was that the ophthalmologist that I saw made the comment that the graft I had (which again is a PK, it had never been made clear to me when I had the graft that there were different kinds) is extremely small, which is unusual, and that because of that it is unlikely to last me more than 15 years. This came as a bit of a bombshell as this had never been made clear to me at the time of the surgery, and as I’m only 23 now and was 18 when I had the graft, I’m confused as to why the surgeon would have gone for this. I know that regraftings have a much higher failure rate, and I’m conscious that as a medic I need a certain standard of vision or I can’t continue.

The plus side to it all is that Moorfields have managed to correct me to 6/9 and 6/12 in left and right respectively with RGPs and have said that they might yet be able to improve on that, and I’m very grateful for that and really want to try and get to grips with the lenses. I guess just at the back of my mind there is this worry now that the future with my sight is more uncertain than I thought it was - ok, all of us with grafts live with the chance that one day the graft may fail, but to have a time cap of 15 years put on mine was really quite worrying, and I was wondering if anyone else had had similar experiences / been told similar things?

Posted: Sat 23 Dec 2006 12:23 pm
by jayuk
Vic

I cant recall the data on the success rate against the size of the graft. There is something out there on Medline and Ill try and look for it for you bit later. However. to say that it will last 15 years, IN MY OPINION, is a little off. Bear in mind im not an Optham, but what I do know from the information and knowledge tranfer from my own Optham, is that the smaller the Graft the less chance of rejection as theres less tissue. So Im really concerned on what basis this was concluded!

Life of graft is based on sooo many variables that the list is endless....and whilst I know this is a shock....id kind of wait till your next appt and question this a little.....

Good to see you got that level of correction! :-)

Try and not let the other aspect get you down....and put it at the back of your mind.....

Hope that helps

J

Posted: Sat 23 Dec 2006 12:32 pm
by Alison Fisher
I can't comment on the size of the graft affecting its life span Vic as I know nothing about that but I have had plenty of similar almost throw away, yet potentially devastating, comments made to me over the years. :evil: Some have taken me a long time to get over and feel comfortable with. :(

As with everything KC related no one knows what the future holds for us individually but for myself I now have a 'what will be will be' attitude and just get on with things as if my grafts will last forever otherwise I'd be in a far worse place mentally than I actually am. However, when it comes to worrying about my daughters that's a whole new ball game. :roll:

Posted: Sat 23 Dec 2006 12:33 pm
by jayuk
Found it found it!

lol

Take a read of this...its just ONE but there were a good 3 or 4 saying the same thing about size of graft

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Risk factors for corneal graft failure and rejection in penetrating keratoplasty
Kenji Inoue1, Shiro Amano1, Tetsuro Oshika1 and Tadahiko Tsuru2

Purpose: To evaluate risk factors for graft failure and allograft rejection after penetrating keratoplasty (PK).

Methods: We retrospectively studied clinical results of PKs in terms of graft survival and rejection-free graft survival rates. PKs were done on 271 eyes between 1987 and 1997. Clinical results were analyzed by Kaplan-Meier's life table method and the log-rank test. Relative risks and adjusted survival probabilities for each value of the factor were compared with the risk for a specified reference value.

Results: The overall rates of graft survival and rejection-free graft survival in 10 years after PK were 79.3% and 77.9%, respectively. Higher relative risk of graft failure was associated with corneal vascularization (relative risk for within one quadrant=1.67, two quadrants=2.37, three or more quadrants=3.39), regraft (relative risk for one failed previously graft=2.08, two or more failed previously graft=2.65), aphakia (relative risk=2.17) or pseudophakia (relative risk=3.02), presence of anterior synechia (relative risk=2.91), presence of posterior synechia (relative risk=2.56), long (more than 85 minutes) operation time (relative risk=2.20), and older (more than 50 years) recipient age (relative risk=2.38). Higher relative risk of rejection was associated with corneal vascularization (relative risk for within one quadrant=2.35, two quadrants=2.03, three or more quadrants=2.63), long (more than 85 minutes) operation time (relative risk=1.47), and younger (less than 60 years) donor age (relative risk=2.10). There was no association between graft failure or allograft rejection and graft size or suture technique, respectively.

Conclusion: The risk factors for graft failure after PK were corneal vascularization, regraft, aphakia or pseudophakia, presence of anterior synechia, presence of posterior synechia, long operation time, and older recipient age. The risk factors after PK for allograft rejection were corneal vascularization, long operation time, and younger donor age.

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Posted: Sat 23 Dec 2006 2:19 pm
by Andrew MacLean
Vic

I had always understood that one reason for the normal use of smaller size grafts was that, in the event of their needing to repeat the procedure they could get progressively larger. I have heard of one patient who had seven grafts in the same eye until the last one took. This was, perforce, the largest of the seven.

Andrew

Posted: Sat 23 Dec 2006 5:08 pm
by GarethB
My understanding today is that topography is used to determine the extent of the KC as the readings given are the corneal thickness. So basically they try and cut out as much of the deseased area as possible. This was one of the reasons DALK was developed to they could use larger disks if needs be and for those who's KC was very much to the corneal margin without increasing the risk of rejection.

At the last birmingham meet the guest speaker said grafts have a 10 year life span, but some there like me have grafts that are older than 10 years, in fact bot of mine are nearly 20 years and the grafts are fine. My problem is with my cornea that remains and the graft is attached to. Both of my grafts used a 7.5 mm disc which I think is quite a large graft to have.

Some think I have abused my grafts as I have worked down sewers, mines, on oil rigs, up chimneys and with my racing too. Fact is I beleive I owe it to the donours to live life to the full and enjoymyself.

Posted: Sat 23 Dec 2006 6:49 pm
by Louise Pembroke
It's amazing, these throwaway comments about graft life spans can leave us reeling, I certainly keep wanting to know of 'old' grafts, people who have had them for 30, 40 and 50 years. Wish there was a central place where graftees [internationally] could report to every 5-10 years for a brief progress report, as this would aid research to look at the very long term survival.

Vic, you're gonna be great with RGP's, I'll sit beside you and ply you with choccie and tea until you can handle them!

Posted: Sat 23 Dec 2006 7:05 pm
by jayuk
Louise

I agree...but the sole reason for this, is that when people have them...they drop out of the system.....Id hate to think of the number in say the last 25 years that have had grafted, for example, at Moorefields...that have recovered and dropped out of the system...if you relate that to the amount that Moorefields say that have treated against the ones not sen after...thatw ould be interesting reading.....

J

Posted: Sat 23 Dec 2006 7:12 pm
by Louise Pembroke
Sure would Jay. I can see the problems, people drop out, move, emmigrate, die. One way around this would be to give all graftees a contact address which they could write/email from anywhere in the world every 5-10 yrs to let researchers know whether it's survived etc. Of course not everyone would do it, but I would if they promised to send me back a bar of choccie or cake :D

Posted: Sat 23 Dec 2006 7:35 pm
by jayuk
Well Im sure they have the informatuon on total performed.....and im sure they can also get the data on how many stil in the system

Probably a maximum of 5 man days of work.....worse case.....but its NHS....YIKES! so mulitply that by 10, get a manager and a supervisor and a project plan, and then possibly lol