JAN 09, 2012
This prospective study published in Ophthalmology in December 2011 reports one-year outcomes for Descemet’s membrane endothelial keratoplasty (DMEK). The results suggest that it is a promising procedure that provides rapid visual recovery and predictable refractive outcomes. Visual acuity results during the first year after DMEK were better than those typically reported for other endothelial keratoplasty techniques, such as Descemet’s stripping automated endothelial keratoplasty (DSAEK), with less refractive change and similar endothelial cell counts but a higher rebubbling rate.
The study included 112 patients (136 eyes) with endothelial dystrophy, pseudophakic bullous keratoplasty or a failed previous graft who were seen at one of two centers. DMEK alone was performed in 110 eyes or combined with either phacoemulsification and IOL implantation (23 eyes) or pars plana vitrectomy (three eyes).
Excluding eyes with pre-existing ocular comorbidities or those lost to follow-up, mean BSCVA at one year improved from 0.51 logMAR (20/65; range, 20/20 to counting fingers) to 0.07 logMAR (20/24; range, 20/15 to 20/40). Forty-one patients achieved BSCVA of 20/20 or better, 80 percent were corrected to 20/25 or better and 98 percent achieved 20/30 or better. Most of the visual improvement occurred within three months, with modest but continued improvement up to one year.
There was a nonsignificant refractive hyperopic shift of 0.24 D at one year. Mean endothelial cell loss at one year was 36 percent, with most of the loss occurring during the first three months after surgery. DMEK graft creation could not be successfully completed in six cases (4.2 percent). Eleven grafts (8 percent) demonstrated primary failure and one eye (0.7 percent) experienced secondary failure resulting from endothelial rejection. Immunologic rejection episodes were documented in seven eyes (5.1 percent) during the first postoperative year, all of which occurred at the center that tapered topical steroids earlier.
The authors conclude that DMEK offers true component replacement of endothelial cells. However, additional and longer-term data on graft survival, endothelial cell loss and the optimal steroid-dosing regimen to prevent rejection episodes, as well as refinements in technique, are needed.