EyeWorld India June 2015 Issue

Corneal lamellar surgical procedures June 2015 30 EWAP SECONDARY FEATURE DSAEK in the cornea spotlight by Maxine Lipner EyeWorld Senior Contributing Writer Sizing up the transplant technique F or patients with endothelial disease, successful treatment does not necessarily hinge on a high-wire Descemet’s membrane endothelial keratoplasty (DMEK) approach. The easier-to-perform Descemet’s stripping automated endothelial keratoplasty (DSAEK) technique can offer outcomes that are close to DMEK, but it is possible for a wider number of surgeons, according to Massimo Busin, MD, Department of Ophthalmology, Villa Igea Hospital, Forlì, Italy. With DSAEK, Dr. Busin finds that preparing and evaluating the slightly thicker donor tissue is easier for eye banks, as is the transplant process for surgeons. Kristiana D. Neff, MD, Carolina Cataract & Laser Center, Charleston, SC, concurs. “The tissue is more rigid and easier to implant so there is less surgical manipulation needed to get the tissue in place and thus less iatrogenic tissue loss,” she said. Neda Shamie, MD , associate professor of ophthalmology, University of Southern California (USC) Eye Institute, Los Angeles, AT A GLANCE • Most patients with endothelial disease can benefit from DSAEK. • DSAEK can be easier to perform than DMEK for many. • Thinner DSAEK tends to offer better visual results with lower rejection rates. said that the learning curve for DSAEK is not as steep as the one for DMEK. “DMEK is more challenging for someone who is early in the learning curve,” Dr. Shamie said. She added that it is typically recommended that practitioners first get DSAEK under their belt and become comfortable with working in the anterior segment with a graft before trying DMEK. Also, the clarity of the host cornea does not play as big a role in DSAEK cases, Dr. Shamie said. “Because there is thickness to the donor DSAEK graft, you can perform DSAEK surgery in a cloudier cornea than you can with DMEK,” she said. “With a cornea that’s extremely edematous or has some scarring, DSAEK can still be performed because it’s not as important to see clearly through the recipient cornea.” Dr. Shamie also finds that the risk of detachment of the graft or the need for rebubbling is less in DSAEK cases than in DMEK. “One of the benefits is a lower chance of needing to go back to the operating room,” she said. At the start DSAEK has come a long way since its inception, Dr. Busin said. It emerged toward the end of the last century when interest in developing techniques for selectively transplanting only part of the cornea arose, he said. There were basically two approaches at the time. “In one, you would create a flap like for LASIK and perform an almost full-thickness trephination underneath and replace the piece under the cap,” Dr. Busin said. In the other technique, which later became known as DSAEK, donor stroma and endothelium was attached to the back of a full cornea. Dr. Busin first performed this in rabbit eyes in 1996 and presented at the American Academy of Ophthalmology on it that year. Eventually he abandoned this initial approach, viewing the technique as awkward. “What I didn’t know at the time was you don’t need stitches,” Dr. Busin said, adding that by stitching the lamellar, the ensuing damage was so extensive that it would not survive in a human being. However, when Gerrit Melles, MD, PhD, showed in 1998 that all that was needed to get the layers to stick to each other was an air bubble, everything changed, he said. “This revived the technique, and around 2002 the first DSEK [Descemet’s stripping endothelial keratoplasty] was performed in a human,” Dr. Busin said. “Initially the donor (tissue) was prepared by The extremely thin DMEK tissue can be dif cult to manipulate. DSAEK can be easier to perform than DMEK and may offer similar outcomes. Source (all): Kristiana D. Neff, MD