Giving sight back
Consultant ophthalmic surgeon, Professor Christopher Liu, was made an Officer of the British Empire (OBE) in the New Year’s honours list. He shares insight into pioneering DMEK corneal transplantation in the UK
01 As a consultant ophthalmic surgeon, I came across Descemet’s membrane endothelial keratoplasty (DMEK) in early 2010 and travelled to Germany in January 2014 to learn the procedure.
It is a partial-thickness corneal transplant technique that involves the selective removal of the patient’s Descemet’s membrane and endothelium, followed by the transplantation of donor corneal endothelium and Descemet’s membrane.
DMEK is more difficult for ophthalmic surgeons to perform than other corneal transplant procedures as there is no corneal stromal tissue transplanted. However, there are many advantages to this, including the visual result being much better, the rejection rate being much lower and one donor being used for up to four eyes.
02 As a consultant surgeon of more than two decades, it is important for me to learn and pioneer new techniques.
My philosophy on learning is that I am not usually the earliest adopter because I like to learn more about a technique and ensure that there is evidence of its value before I go and learn it.
However, when I decide to learn a new surgical technique, I will always go and see an expert for this. Taking this approach, you can go far and wide as a result. When it came to DMEK, I learned from Professor Fredrick Kruse in Germany and Professor Mark Muraine in France.
While I recommend learning new techniques from experts, I also recommend practising in a wet lab environment and simulated surgery. I would then ensure that my first few cases are supervised by an expert.
"The visual benefits that DMEK brings patients is outstanding and I think that all patients should be given the best proven treatment that is suitable for them"
03 I understand that DMEK is a difficult procedure, and many surgeons choose not to switch from other procedures that they feel are sufficient due to the learning curve involved.
However, having performed an estimated 50 procedures in the last four years, I have invented several developments which will enhance the technique and make it easier to perform.
First there is an ex-vivo human corneal model, which allows surgeons to practise every single step of DMEK surgery. Secondly, there are Liu vents in the periphery host cornea which allows jets of fluid to unfold peripheral graft folds. Thirdly, there is the Liu twirl, which frees up the scrolled graft within the injector before the insertion of the graft into the anterior chamber, making for more atraumatic introduction. Finally, there is a new DMEK injector under development that will make the insertion and unfolding of the scroll in the correct orientation and centration very easy, thus making for a much easier learning curve.
I always want to take techniques further because, as professionals, we cannot be at a standstill, we have to improve. Nothing, however good it is, is perfect. Therefore, it is important to strive further towards perfection. You will never get there, but step by step, you make it a bit better and easier each time.
Cataract surgery is a good example of this. If you look back at when cataract surgery was first established it was quite different to the techniques that we use today and that is because it has developed and improved.
04 I really believe in this procedure and welcome surgeons to Sussex to learn it. I would set up a wet lab for them to practise the procedure in and I am willing to travel to them to supervise their first procedure or two.
I would do this because I believe in this technique and want to get it out there and being performed by the many rather than the few.
The visual benefits that DMEK brings patients is outstanding and I think that all patients should be given the best proven treatment that is suitable for them. This treatment is better and it is proven so, so patients should be offered it. But they can’t be offered it if surgeons do not do it.
05 When it comes to patients’ reactions following this corneal transplant technique, they are overjoyed and feel that they have been given their lives back.
The results of DMEK offer patients very clear vision; colours are vivid, edges are sharp and you can see far away.
I have spoken to patients with corneal endothelial dysfunction who have received DSAEK in one eye and DEMEK in the other eye; they always say they prefer the DEMEK eye because it is so much clearer and the quality of vision is so much better.
It is the improved results that made me confident that this technique is worthwhile investing the time and energy in to go and learn it, to further improve it and to try to widen its appeal among colleagues.