NEW YORK (Reuters Health) - Descemet membrane endothelial keratoplasty (DMEK) offers advantages over the more widely used Descemet stripping endothelial keratoplasty (DSEK) for the surgical treatment of corneal endothelial dysfunction, according to an Ophthalmic Technology Assessment from the American Academy of Ophthalmology.
"DMEK should be choice of procedure for uncomplicated endothelial failure/dysfunction as a result of Fuchs endothelial dystrophy, pseudophakic bullous keratopathy, or other corneal endothelial dystrophy,” Dr. Sophie X. Deng from Stein Eye Institute at the University of California, Los Angeles, told Reuters Health by email.
With DMEK, only the endothelium and Descemet membrane are transplanted, whereas with DSEK, the endothelium, Descemet membrane and a thin layer of posterior stroma are transplanted onto the surface of the host posterior stroma after descemetorhexis (excision of the host Descemet membrane).
Dr. Deng and colleagues on the Cornea and Anterior Segment Disorders Panel reviewed 47 articles on the safety and outcomes of DMEK and sought to determine whether it offers any advantages over DSEK in terms of visual recovery, outcomes and complications.
All seven studies that directly compared the visual outcomes of DMEK and DSEK showed a better visual recovery after DMEK than after DSEK. In six of those studies, DMEK achieved a significantly better mean or median best-corrected visual acuity (BCVA) than DSEK, the panelists write in Ophthalmology, online September 16.
The mean rate of primary-graft failure was 1.9% after DMEK, compared with 5% after DSEK. The mean rejection rates during follow-up periods of up to eight years were 1.9% after DMEK and 10% after DSEK.
Endothelial cell loss in most studies was comparable with DMEK and DSEK.
“A good number of surgeons still do not believe that DMEK has advantages over DSEK,” Dr. Deng said. “Because the technique of DMEK is more difficult, there has been resistance from these surgeons to transition to DMEK. The surprising finding is that the complications associated with the procedure after not higher in DMEK than in DSEK after the surgeon’s learning curve.”
“Although DMEK has been shown to be performed successfully in eyes with prior vitrectomy and trabeculectomy or glaucoma drainage device placement, the feasibility of performing DMEK in other complicated eyes, such as those with an anterior chamber intraocular lens, large iris defect, or absence of lens support, needs to be investigated further,” the researchers note. “In such eyes with abnormal anatomy, DSEK remains the preferred procedure to treat endothelial dysfunction.”
They add that future randomized controlled clinical trials are needed to confirm these findings.
Dr. Marianne Price, executive director of the Cornea Research Foundation of America, in Indianapolis, Indiana, told Reuters Health by email, "Currently, DMEK provides the fastest and most reliable visual recovery for patients with corneal endothelial dysfunction. Endothelial regeneration techniques may eventually be preferable for patients with Fuchs’ dystrophy, but further refinements are needed.”
“Advances over the past 2 decades, culminating in DMEK, have transformed corneal endothelial dysfunction from a blinding condition with a long, complicated surgical recovery into a readily treatable condition with an excellent prognosis of rapidly regaining 20/20 vision,” said Dr. Price, who was not involved in the review.
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