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Learn DMEK based on protocols from NIIOS
Fellows at the institute approach this surgery systematically and effectively through ‘read, watch, practice and ask.’
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There are parallels between DMEK vs. DSEK and phaco vs. ECCE. While DMEK might be technically more challenging, its adoption is increasing with evidence supporting its superiority. Read how the Dutch learn new techniques at their institute and be inspired.
Anthony P. Khawaja, MB BS, MA (Cantab), MPhil, FRCOphth
Chair of the SOE Young Ophthalmologists committee
With the exception of a few staunch holdouts, almost everyone now agrees: Compared with conventional Descemet’s stripping endothelial keratoplasty, Descemet’s membrane endothelial keratoplasty offers better and faster visual results, less allograft reaction and fewer severe complications such as secondary glaucoma and cataract. In every head-to-head study (evaluating patients operated with both techniques: one eye DSEK, one eye DMEK), patients subjectively prefer the vision in their DMEK eye. And frequently, disappointing acuities after DSEK can be dramatically improved by replacing the grafts with DMEKs.
Despite these admitted superiorities, DMEK nevertheless remains less popular in the United States than DSEK, largely because the operation is still perceived as too difficult for the average ophthalmologist. Happily, this belief may be mistaken. With a little practice and the proper materials, virtually any corneal surgeon — including residents — may enjoy consistently excellent results. Below, we provide our recommendations for how to learn DMEK surgery, which is the same program followed by the fellows at the Netherlands Institute for Innovative Ocular Surgery (NIIOS) at the beginning of their training.
Read
At the NIIOS, we primarily use the standardized no-touch technique, first published in 2011 by Dapena and colleagues, for our DMEK surgeries. As a result, this is the first paper the fellows read. The manuscript provides a convenient introduction for beginning surgeons because it outlines the procedure step by step, with artistic illustrations and clinical photographs of the key elements, as well as advice about patient selection, preoperative considerations and postoperative care.
Second, we learn the ancillary graft unfolding tactics, which are useful instead of or in combination with the standardized no-touch technique. These were originally described by Liarakos and colleagues in 2013 and are particularly helpful in “difficult” eyes, such as those with glaucoma shunts or anterior chamber IOLs, or eyes that are aphakic or post-vitrectomy.
Jack Parker, MD, shaking hands with young colleagues at a meeting.
Image: Parker J
Third, we read Yeh and colleagues’ 2013 article on the management of graft detachment, which is DMEK’s most common complication, using serial anterior segment OCT images to predict which detachments will spontaneously resolve and which will require intervention.
All of these articles may be found separately or bundled together with other tips and tricks for the operation in a textbook written by the NIIOS team (www.niios.com).
Watch
After reading the theory, our next step is to watch actual surgery. At the NIIOS, all operations are recorded on video. Many clips from such cases, and even a handful of complete, unedited surgeries, have been uploaded to YouTube and are available via our website at https://www.youtube.com/user/NIIOSonVideo.
Practice
Conveniently, DMEK can be practiced in the wet lab. The necessary grafts are quickly and easily prepared from cadaveric corneoscleral rims unsuitable for human transplantation using cheap and widely available instruments via the method described by Groeneveld-van Beek in 2013. With the graft in hand, the operation itself can be simulated by mounting the leftover corneoscleral rim atop an artificial anterior chamber and then performing the standard DMEK operation inside this makeshift “eye.” Otherwise, if human tissue is unavailable for practice, a porcine eye DMEK model, described by Droutsas and colleagues, faithfully replicates the procedure.
Ask
Of course, a major benefit that the NIIOS fellows receive is excellent instruction. And although the NIIOS hosts surgical courses “in house” year round, as well as on site at most major international ophthalmological meetings, for many surgeons, in-person attendance can be difficult. As a result, the NIIOS has recently begun broadcasting live, from the operating room, with cameras projecting the operation online in real time. The surgeons, fellows and assistants all wear headset microphones and invite interested viewers to log in, ask questions and participate in discussion.
There are many good ways to learn DMEK, but the above program is the one we use ourselves at the NIIOS. So for all those looking for a place to begin, this might be worth a try.
- References:
- Dapena I, et al. Arch Ophthalmol. 2011;doi:10.1001/archophthalmol.2010.334.
- Droutsas K, et al. Acta Ophthalmol. 2014;doi:10.1111/aos.12371.
- Groeneveld-van Beek EA, et al. Acta Ophthalmol. 2013;doi:10.1111/j.1755-3768.2012.02462.x.
- Guerra FP, et al. Cornea. 2011;doi:10.1097/ICO.0b013e31821ddd25.
- Liarakos VS, et al. JAMA Ophthalmol. 2013;doi:10.1001/2013.jamaophthalmol.4.
- Price MO, et al. Curr Opin Ophthalmol. 2013;doi:10.1097/ICU.0b013e32836229ab.
- Yeh RY, et al. Ophthalmology. 2013;doi:10.1016/j.ophtha.2012.08.011.
- For more information:
- Jack Parker, MD, can be reached at jack.parker@gmail.com.
- SOE Young Ophthalmologists website: http://soevision.org/yo.
Disclosure: Parker reports no relevant financial disclosures.