Bob: Dr. Terry thank you for giving us some of your valuable time with this interview. All of us at the Corneal Dystrophy Foundation and Fuchs Friends appreciate it very much.
Dr. Terry: Thanks, Bob. It is a pleasure for me to do the interview as the organization of the Corneal Dystrophy Foundation and the members of Fuchs Friends have helped so many patients over the years.
Bob: It has been said that you performed the first partial transplant in North America. When was that and can you give us a brief history?
Dr. Terry: It has indeed been an incredible journey these past 19 years! It was in the late 1990’s that I first began working in the field of lamellar (partial thickness) corneal transplants. The year 1998 was a big one for me in that my wife Cindy gave birth to our twin boys, Charlie and Nicholas, and I had “night duty” for feeding them between 10:00 pm and 4:00 am every night so Cindy could get some rest.
Well, I figured then that if I was up anyway, I might as well catch up with the reading of all my scientific journals. It was a night in December 1998 that while feeding the boys their bottles, I came across an article by a little known Dutch physician named Gerrit Melles. It was an obscure article describing a surgical technique in eye bank eyes and in one live monkey whereby he removed the back part of the cornea using a partial thickness pocket and then replaced the recipient endothelial cells with a similar partial thickness piece of donor tissue containing healthy endothelial cells.
Now this had been done before, but what was unusual about this article is that he was able to keep the tissue in place with just an air bubble and no sutures. Well, this was such a surprise to me that I almost dropped my son Charlie on the floor! I immediately realized the possibilities that this held for so many of my patients. I contacted Dr. Melles by email to ask how to buy the instruments for this surgery, but he said that he only had one set and they were not available.
The first human surgery had not been done yet. I was on an instrument development panel for Bausch and Lomb company at that time, and so I contacted them, sent them drawings on a piece of paper of what I felt I needed and 6 weeks later I had the initial working prototypes for this new surgery. The fun part about designing the instruments is that I also got to name them: the Cindy scissors, the Charlie forceps and the Nick pick!
Anytime there is a new experimental surgical idea, it needs to be fully worked out in the laboratory before it is ever used on patients…that is the only ethical thing to do. So I spent the next 9 to 12 months working on weekends and nights with countless eye bank cadaver eyes to perfect the procedure so it could be safely done in a human. I also worked with my ethics committee (called an IRB or “institutional review board”) to make sure that when the time came to move on to a clinical trial, the patients true informed consent would be obtained and their rights protected.
Finally, in March of 2000 my IRB gave me the go-ahead, and one of my long time patients with Fuchs Dystrophy agreed to be the first patient to undergo this new procedure that I named “Deep Lamellar Endothelial Keratoplasty” or DLEK. So in March 2000 I did the first endothelial keratoplasty surgery in North America, the second time it had been done in the world. (Dr. Melles had published a first single case report in 1999). This patient ended up seeing 20/40 with no glasses in just a couple weeks, so much better than having a full thickness transplant, so my IRB allowed me to do another case; and then another and then another…all of whom did well.
So well that I presented the cases and the video of the first patient at the American Academy of Ophthalmology meeting that fall of 2000. I thought that this new surgery with it’s spectacular results compared to full thickness PK surgery would take off right away, but unfortunately, some surgeons didn’t believe the results could be so great and others felt the surgery was just too difficult. It took nearly 2 years (and several publications by me and by Dr. Melles) before endothelial keratoplasty started to gain acceptance as a legitimate procedure.
Slowly, with more surgeons involved, more ideas came to the fore and the DLEK procedure evolved into Descemet stripping endothelial keratoplasty (DSEK) then Descemet stripping automated endothelial keratoplasty (DSAEK) and finally Descemet membrane endothelial keratoplasty (DMEK). My team and I here in Portland have tried to lead the way in each of these procedures, publishing over 130 scientific articles and book chapters, and all the while making sure that each advanced surgery was carried out in an ethical and loving way for each patient. Yes, it has really been an incredibly gratifying journey to be a part of this surgery that has helped so many patients around the world.
Bob: How many DLEK’s, DSEK’s, DSAEK’s, and DMEK’s have you performed?
Dr. Terry: We did a couple hundred DLEK surgeries in the first 3 years (2000-2003) before starting DSEK/DSAEK and we performed about 1,700 of those. We started doing DMEK in 2009, and currently we perform DMEK for over 90% of our cases (100% of Fuchs cases). We have done a little over 1,000 DMEK cases I believe. After a few hundred cases you get pretty good at it!
Bob: In the last two years we have heard a lot about Descemet’s Stripping, a technique which avoids the need for a transplanted tissue. Do you plan to perform this? What’s your opinion?
Dr. Terry: The idea of removing an area of Descemet’s membrane and not replacing those cells with a transplant is very attractive. Corneal transplant tissue is a selfless gift from a grieving family to another hopeful family to restore vision, and so donor tissue is very precious. Anything we can do to preserve the availability of that tissue is a good thing. The results of Descemet’s stripping without transplant so far has had mixed results.
In the few small series that have been published, the technique has worked in most, but not all, of selected patients. What is apparent at this time is that you have to be very careful on who you select for this surgery. The best candidate is a patient with Fuchs dystrophy that has disease ONLY in the central corneal area, with no signs of disease in the peripheral areas. That is a small minority of the patients that I see.
Even with those patients, there is no guarantee that the cornea will heal the stripped area and the patient can be left with severe swelling for weeks and even months. Fortunately, at some point, if healing is not evident, you can do on to do a DMEK to restore vision, but you do not want to wait too long or the chronic swelling could cause scarring which can limit the final vision even with the DMEK “rescue” operation. At this time I am not doing Descemet’s stripping without transplant, but I likely will in the future for the few patients that I feel would truly benefit and have low risk. I feel strongly, however, that this procedure should be done with full IRB approval (ethics committee approval) so that any patient undergoing it fully understands the risks and alternatives.
Bob: Many new developments are taking place in your field. What do you the most interesting and promising for the years ahead?
Dr. Terry: The most recent development that is so exciting is the new availability of “Pre-Loaded DMEK” tissue. This was developed by our eye bank, the Lions VisionGift, here in Portland, Oregon, and has been named by them “Patient Ready DMEK”. The concept is that no longer does the surgeon have to prepare the tissue in the operating room.
The eye bank can now strip the donor tissue, stain it, cut it to size and even load it into the Straiko injector, and then it is shipped to the surgeon in nutrient solution. We have been using “Patient Ready DMEK” tissue since March 1, 2017 and the results are every bit as good as the DMEK surgery cases before when we were preparing the tissue ourselves.
What is wonderful about this eye banking advance is that it takes the risk of damaging the tissue out of the operating room and so will make DMEK surgery much easier and much more appealing to surgeons that are hesitant to adopt DMEK for their patients. This will increase acceptance of DMEK not only in this country but around the world. Pre-Loaded DMEK tissue is now processed by several eye banks here in the U.S. and available to any surgeon.
Bob: Thank you again for your time. Any final thoughts for our CDF and Fuchs Friends audience?
Dr. Terry: The Cornea Dystrophy Foundation and Fuchs Friends have provided an incredible service to our profession and to our patients. So many of my patients have said that they find not just knowledge from the website, but such comfort in talking with others that “have been there”. I thank all of you for your selfless work and your devotion to others.
