ASCRS 2024: Roundtable discussion on DMEK and DSEK surgery

Rahul S Tonk, MD, MBA, sat down to discuss a roundtable discussion he had on DMEK and DSEK surgery at this year's ASCRS meeting held in Boston, Massachusetts, from Friday, April 5, to Monday, April 8, 2024.

Video Transcript

Editor's note - This transcript has been edited for clarity.

David Hutton:

I'm David Hutton of Ophthalmology Times, ASCRS is holding its annual meeting in Boston. At that event, Dr. Rahul S Tonk is presenting a roundtable discussion titled "Endothelial keratoplasty." Thank you so much for joining us. Tell us about this presentation.

Rahul S Tonk, MD, MBA:

Thank you so much for having had me at the ASCRS meeting to give the roundtable on DMEK and DSEK surgery.

So, the roundtable discussion really pertained to bringing up to speed the latest and greatest on surgical technique and options for really perfecting our DSEK and our DMEK surgeries. So in the United States, we now have about equal shares of keratoplasty being done as full thickness or penetrating keratoplasty. And then a share of DSEK which is Descemet's Stripping Endothelial Keratoplasty. And then finally, a third share of DMEK surgery which is Descemet's Membrane Endothelial Keratosplaty.

And us cornea surgeons love our alphabet soup, but what DMEK gets you is basically a anatomical replacement directly of Descemet's membrane, and endothelial cells. We strip these out of the patient and we replace them layer by layer in a pure anatomic replacement from a donor eye, whereas DSEK involves replacement of the same cells but with a small, thin stromal barrier.

So DMEK has been shown in clinical trials to have better visual outcomes and potentially better longevity or lower endothelial cell rejection risk. However, it is technically a more demanding surgery to learn and to do. DMEK tends to be inserted or injected in a small scroll which surgeons have to unscroll, and then bubble into position. And there are a number of factors that can make that surgery more challenging than the DSEK. And so, our roundtable discussion talked about some of the new pearls that surgeons can use to have successful DMEK surgeries.

When they might choose the old gold standard, DSEK in place of DMEK surgery, or when they might alternatively choose to do a treatment like Descemet's Stripping only which is coming up where Descemet's membrane is stripped but not replaced by a cell transplant. And we also just briefly discussed as well, new endothelial cell regenerative therapies where injectable endothelial cells are on the horizon in clinical trials, and hold some promise in revolutionising the care of some of our patients with endothelial disease.

David Hutton:

And how can this help ophthalmologist provide better results for their patients?

Rahul S Tonk, MD, MBA:

Well, DMEK is really better surgery for patients that I would say qualify for DMEK. And so the the majority of patients that are getting DMEK surgery are going to be folks with endothelial dystrophies like Fuch's dystrophy, or folks that have simple, uncomplicated pseudophakic bullous keratopathy. And in those patients, what's common is that you have fairly good anatomy, we have an intact iris lens diaphragm that allows us to unscroll the DMEK graft and achieve a good gas tamponade and get our best visual outcomes.

And there are surgeons that are pushing the limit for sure in trying to extend DMEK into more complicated eyes. Eyes that have had prior vitrectomies, eyes that have had prior penetrating keratoplasty, eyes that have glaucoma tubes or hardware, and certainly DMEK can be done successfully in some of those eyes. But certainly it is a greater challenge and maybe not the first selected case for surgeons that are learning DMEK, or are still on the learning curve for DMEK. In those cases, the general consensus or I would say most ophthalmologists are still working towards ultra-thin or nano-thin DSEK. Very, very thin DSEK lens in place of DMEK. But what is really also helped the fields move more and more towards DMEK for treatment of Fuch's dystrophy and uncomplicated pseudophakic bullous keratopathy is the support of our eye banks. And our eye banks are now providing us with pre-loaded, pre-prepared tissue where the Descemet's membrane is pre-stripped, pre-marked, pre-punched and pre-loaded into an injectable device some kind of glass cannula, so that the surgeon only has to really worry about injecting inside the interior chamber and then bubbling it in place.

So at a roundtable we talked about a number of different options and tips about how a surgeon would go about unscrolling the DMEK graft successfully. How to tamponade the DMEK graft with either air, SF6 gas or C3F8 gas. And we went on to talk about what the post operative care for patients looks like including re bubbling procedures or regrafting procedures as need be. We also talked about DSEK surgeries and the different ways in which the DSEK lenticulars can be inserted and we now have a number of eye banks that are pre loading DSEK lenticulars into injection devices kind of taking after DMEK to do the same and make the process much easier for our surgeons.