EyeWorld Asia-Pacific March 2012 Issue

41 EW CORNEA March 2012 you use a manual trephination or the laser, surgical technique also matters in the approach; if you’re really devoted to reducing the astigmatism, you can.” He stressed that to do so practitioners need to monitor their outcomes and modify their techniques to drive results in that direction. On the up side, investigators Cordelia CHAN, MD Senior Consultant, Cornea & External Eye Disease Service Singapore National Eye Centre 11 Third Hospital Avenue, Singapore 168751 Tel. no. +65-6227-7255 cordelia_chan@snec.com.sg F emtosecond Laser-Assisted Keratoplasty (FLAK): Is it always superior to conventional keratoplasty? The use of femtosecond lasers in ophthalmology has changed the playing field in cornea surgery and cornea transplantation. A variety of applications have been described, including penetrating, anterior lamellar and endothelial keratoplasty techniques, as well as arcuate relaxing incisions. Unlike manual trephination, femtosecond lasers are able to create extremely precise cuts in donor and recipient corneas. The biggest advantage of the femtosecond laser is its ability to create an endless variety of shapes and angulations in its penetrating and lamellar incisions. The laser-generated multi-planar conformations provide increased wound stability and increased resistance to wound leakage compared to conventional keratoplasty with mechanical trephination. Various incision patterns possible with the femtosecond laser include top hat, dovetail, mushroom, zigzag and Christmas tree configurations which maximize the surface area of the incision and provide increased stability to the graft-host junction. With an improved alignment of donor and recipient, fewer sutures are required, and suture removal can be performed earlier than in conventional keratoplasty. These theoretically translate into a more astigmatically neutral graft, faster visual rehabilitation and better visual outcome for the patient. But is FLAK always superior to conventional keratoplasty? In the article “Focusing on FLAK: Femtosecond technique compared to PK” in the Dec 2011 issue of EyeWorld Magazine, in describing a study comparing FLAK to conventional penetrating keratoplasty (PK), an unexpected finding was that “astigmatic outcomes did not measure up to those in the original investigation”. Ultimately, experience and surgical technique determine the eventual outcome of any cornea transplant. Suturing technique, in particular, is highly varied among surgeons, and is an important factor in the visual outcome of both FLAK and conventional PK, particularly in the early postoperative period. The benefits of a perfectly crafted graft-host interface by the femtosecond laser would obviously be negated if poor suture techniques are employed, resulting in induced astigmatism. Nonetheless, the mechanically stable wound afforded by the femtosecond laser is a major advantage over the wound created in conventional PK, where wound dehiscence following minor trauma years after surgery often plague both patients and surgeons. However, the increased cost of purchasing and maintaining the femtosecond system, the additional time incurred in transporting the patient from one point to another and other logistic issues remain major obstacles in convincing surgeons to adopt this platform for cornea surgery. Editors’ note: Dr. Chan has no financial interests related to her comments. in Dr. Chamberlain’s recent study demonstrated that with the FLAK technique they were able to remove sutures at an earlier time. “We think the designs that the femtosecond laser can cut are inducing faster healing and stronger graft host interface or corneal wounds that may allow us to remove sutures earlier,” Dr. Chamberlain said. “That may allow for earlier visual recovery, and it also cuts down on risks associated with longer-term suture retainment in the cornea.” Clinical possibilities From a clinical standpoint, Dr. Chamberlain sees the femtosecond technology as a major breakthrough in the keratoplasty surgery. “The laser certainly has applications to many types of corneal transplant techniques,” he said. “The one that was primarily examined in this paper was PK, but we and others have also demonstrated the use of the laser in lamellar keratoplasty techniques.” Femtosecond lasers are being used for a variety of other corneal surgeries including limbal relaxing incisions, wedge resection, and even cataract incisions. “I think the real potential is that eventually the software and hardware of femtosecond lasers is going to allow for even more sophisticated designs of corneal cuts that will hopefully eliminate the need for sutures.” Dr. Steinert thinks that use of the FLAK procedure will enable practitioners to fine-tune the surgery with LASIK. “Because we have confidence in the incision and our ability to get the sutures out earlier, we are more often in a position to be able to offer a secondary procedure to patients,” he said. “They have their transplant that heals, they get the sutures out, and then they have LASIK to at least reduce the amount of optical correction that they would need in glasses and to improve the quality of their vision.” Cost remains a factor, with the laser itself running in the neighborhood of US$300,000. While many already have the laser to perform the FLAK procedure, those with older versions need a US$50,000 upgrade. Dr. Chamberlain said that there’s also a click fee of about US$300 for cutting the patient’s cornea as well as one for the donor cornea prepared at the eye bank. “Insurance will pick up the fee that the eye bank charges but will not pick up the cost that the surgeon has to incur cutting the patient’s cornea in the operating suite prior to surgery,” Dr. Chamberlain said. “Currently the problem with that is Medicare doesn’t reimburse.” As a result, the surgery center usually ends up absorbing the extra cost, although in a few rare instances this is passed on to the patient. Overall, Dr. Chamberlain sees the femtosecond laser as potentially making the FLAK procedure safer. “This is probably a first step in allowing us to explore more sophisticated ways to make incisions in corneas, ways that will cut down on the requirement for sutures, which are a major risk factor for astigmatism and wound complications,” he said. “Ultimately I think that the femtosecond laser is going to lead to a safer outcome and probably an earlier visual recovery after corneal transplant surgery.” EW Editors’ note: Dr. Chamberlain has no financial interests related to this article. Dr. Steinert has financial interests with Abbott Medical Optics (Santa Ana, Calif., USA). Contact information Chamberlain: 503-475-7587, chamberw@ohsu.edu Steinert: 949-824-0327, steinert@uci.edu