Descemet's Membrane Endothelial Keratoplasty (DMEK)
Descemet membrane endothelial keratoplasty (DMEK) is the most exciting option available to treat the decreased vision and swollen, cloudy corneas seen in Fuchs Dystrophy, bullous keratopathy, and other causes of poor corneal endothelial function. There are three generations in the evolution of corneal transplantation and DMEK is the third and newest. It has been shown to offer patients the best chance to see 20/25 or better, resume normal activities quickly, and avoid vision-threatening rejection episodes. This is because compared to the first generation (penetrating keratoplasty, PKP) and second generation (DSEK) options, DMEK is the most anatomical repair possible – just one cell layer (the endothelial cells) and a thin membrane all of which is only 15 to 20 microns thick.
Surgery is performed in an outpatient surgery center located conveniently in our building, meaning there are no new locations to find and patients do not need to enter or be admitted to a hospital. Anesthesia is given intravenously and with eye drops. The diseased innermost layer of the cornea is removed carefully and the corresponding thin layer from a healthy donor cornea is put in its place. The transplant is held in place by only an air bubble, requiring patients to lay flat on their backs with their faces directed upwards immediately after surgery to float the bubble into place. The bubble goes away within the first week and as it does, patients do not need to lay flat as much. The surgery can be combined with cataract surgery for patients who require both.
DMEK has provided such quick improvement in vision with such a reduced risk of rejection that we are now having patients opting to have their two eyes with Fuchs operated on 1 to 2 weeks apart with or without cataract surgery.
Descemet’s Membrane Endothelial Keratoplasty (“DMEK”) is the latest iteration of endothelial keratoplasty. It leaves the patient’s cornea closer to its original condition than any other transplant technique.
Benefits of DMEK:
- 2.8 mm or smaller corneal incision
- No increase in corneal thickness
- No refractive shift from donor graft
- Ability to pre-operatively plan astigmatism management to reduce or eliminate pre-operative cylinder
- No changes or guesses for “fudge factors” with IOL calculations
Like other forms of endothelial keratoplasty, DMEK involves a whole new learning curve. It has some similarities to DSEK, but also a number of dramatic differences in donor preparation, manipulation in the eye, and post operative care.