EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/194331
October 2013 continued from page 111 SEE US AT AAO AT BOOTH 3729 Increase patient flow and overall practice efficiency. Increase profits. Varitronics can show you how! See more patients in the same amount of time without increasing staff. Var Varitronics, the leader in Non-Verbal Inte Interoffice Communications for over fou four decades, offers the most feature-rich sys systems on the market today. Our custom designed Call Systems will streamline des the way you work so that you can decrease your patient's waiting time d while increasing your staff's efficiency. Wall panel and pager Call, email, or visit our web site today to see how easy it is to benefit from the efficiency of Varitronics' Call System. Call Systems are available for both new and existing construction. CS 2000 Wireless System Leading the way in Interoffice Communications 800.345.1244 email:varimed@varitronics.com www.varitronics.com able to prove the layer existed by simulating corneal grafts and transplants on donor eyes. They injected air into the cornea to separate each layer, and then took images with electron microscopy. Researchers were able to completely peel off Descemet's membrane from a big bubble without deflating it, Prof. Dua said. With electron microscopy, they could see the peeled DM had banded and nonbanded zones. "This confirms that the posterior wall of the big bubble is made up of DM and another layer of tissue," Prof. Dua said. The deep stroma and Dua's layer are separated to form this bubble, which Prof. Dua calls a type 1 bubble. "The old Descemet's membrane bursts," Prof. Dua said, explaining that during his simulated corneal transplants the Descemet's membrane was surgically removed, causing the air bubble to burst or tear. Researchers dubbed this a type 2 bubble, which he said occurred in a minority of attempts. The discovery of Dua's layer could affect how acute hydrops, descemetocele, and pre-Descemet's dystrophies are treated, but researchers are continuing to study how. What's new in DMEK? Marian Sue Macsai, MD, Chicago, gave a presentation during the PanCornea session on "Corneal endothelium transplantation: evolution of techniques." The benefits of DMEK include true anatomic replacement of the tissue, potentially better vision and quicker rehabilitation, rapid visual recovery and smaller incisions, though it is not without its drawbacks, Dr. Macsai said. First, it is not an easy surgery to learn, and there is tissue waste in the preparation stage. "There is extensive endothelial manipulation for preparation and implantation," Dr. Macsai said, adding that the procedure also calls for up to 63% rebubbling. Still, there are new developments in DMEK that may help, Dr. Macsai said. Using the tapping technique with a small bubble in the anterior chamber or no bubble at all in the AC may make unfolding the tissue easier. And, according to Mark Terry, MD, Portland, Ore., surgeons may be able to decrease the detachment rate from more than 30% to less than 3% by using Sf6 gas isoexpansile at 20% to position the tissue against the stroma. Eye banking symposium Donald Tan, MD, Singapore, discussed the clinical challenges for corneal transplantation in Asia during the Eye Bank Symposium. Problems such as late-stage endothelial disease, poorer access to follow-up care, inflammatory scarring, active keratitis, ocular surface disease, and higher risk of allograft rejection and graft failure concern transplant surgeons there. The solutions, Dr. Tan said, are selective lamellar keratoplasty, ocular surface transplantation, keratoprosthesis surgery and adequate eye banking opportunities with more corneas and better standards. "Corneal transplantation around the world is shifting from conventional PK to the emerging forms of selective lamellar keratoplasty, namely anterior lamellar keratoplasty and endothelial keratoplasty, but PK continues and will continue to play an important role in keratoplasty surgery worldwide, especially in developing countries," Dr. Tan concluded. "The lamellar revolution holds great promise." What about lens extraction for glaucoma? Lens extraction remains a controversial option for treatment of acute angle closure glaucoma, according to speakers during the first glaucoma session of the day. The procedure may be effective when compared with iridectomy, but it involves great surgical risk, said Roberto Murad Vessani, MD, Brazil, who gave a talk comparing treatment options. Anterior chamber paracentesis also presents great challenges, Dr. Vessani said.