EyeWorld Asia-Pacific March 2011 Issue

Index to Advertisers Bausch & Lomb Page : 5 Phone: 585-338-6000 Fax: 585-338-6007 www: bausch.com Moria Page: 26 Moria SA Phone: +33 (0) 1 46 74 46 74 Fax: +33 (0) 1 46 74 46 70 E-mail: moria@moria-int.com www.moria-surgical.com Moria in China Phone: +86 21 5258 5066 Fax: +86 2 5258 5067 www.moria-surgical.com.cn Oculus Optikgeräte GmbH, Germany Oculus Asia Ltd, Hong Kong Page: 15 Phone: +852 2987 1050 Fax: +852 2987 1090 E-mail: info@oculus.hk www.oculus.de, www.oculusexperts.com Rayner Supplement Phone: +44 1273 205401 Fax: +441273 324623 E-mail: iol_enquirires@rayner.com www.rayner.com STAAR Surgical Page: 23 Phone: +65 6829 2146/+65 8100 7731 E-mail: atan@staarag.ch www.staar.com , www.iclinfo.info Technolas Perfect Vision GmbH Page: 10 Phone: +65 6592 0792 Fax: +65 6250 1060 E-mail: Y.Ng@technolaspv.com , M.Soon@technolaspv.com, A.Koh@technolaspv.com www.technolaspv.com, www.intracor.net 31 EW CORNEA March 2011 Post-PRK epithelium not firmly attached to the cornea; patients may fare better with LASIK Source: Daljit Singh, MD Corneal transplant patients ... seeing the refractive light by Maxine Lipner Senior EyeWorld Contributing Editor From arcuate keratotomy to LASIK, refractive procedures increase transplant acuity F or patients who have undergone corneal transplant, subsequent refractive surgery to correct astigmatism or anisometropia is a viable option, according to Prabjot Channa, MD, assistant professor of ophthalmology, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY, USA. In a recent review published in the May issue of Current Opinions in Ophthalmology, investigators considered the gamut of refractive options for post-corneal transplant patients. Astigmatism plagues many patients who have undergone penetrating keratoplasty. “Most people will get some amount of astigmatism,” Dr. Channa said. “The average is about 4–5 D, if not more.” This may increase dramatically after suture removal and can sometimes be unpredictable. In addition, other refractive errors may be present. “The problem is not only that patients can get astigmatism but they can also get associated hyperopia or myopia,” Dr. Channa said. Post-transplant dilemma In cases where the difference in refractive error between the two eyes is greater than 3 D, it can result in significant visual trouble. “The graft may be successful, it may be clear, but as far as getting binocularity and functional rehab for the patient, that’s something else,” Dr. Channa said. “The patient may not have depth perception because now he can’t use both eyes together.” In many cases, neither contact lenses nor glasses are a viable option for such patients. Dr. Channa stressed that many of these patients are unable to be fit with contact lenses and that spectacles can only correct differences between the eyes to a certain degree. In looking at refractive surgery, the hope was that it could make the difference for post-corneal transplant patients. “With the choices that are available we may not totally get rid of glasses or contacts but at least it may be more amenable to treating the patient with glasses by decreasing the astigmatism and the spherical equivalent,” Dr. Channa said. Investigators considered how laser refractive procedures as well arcuate keratotomy and IOL use fared in these post-transplant patients. As a rule, post-transplant patients tended to do very well with refractive surgery, Dr. Channa found. “These patients did get good results,” she said. “They could be corrected and they had a resolution of their high astigmatism and spherical anisometropia.” Weighing refractive options Results suggested that LASIK might fare better in these patients than PRK. “There was some regression and they had to use MMC in some of these patients,” Dr. Channa said. “But LASIK may be better.” One paper suggested that a two- step LASIK procedure might offer some advantages. “They found that it was better to wait and to do it in two steps to allow some of the biomechanical properties of the cornea to settle in and present a more predictable outcome after the laser ablation,” Dr. Channa said. They also considered incisional keratotomy and what role the femtosecond laser might play. Investigators considered a study looking at how results with the mechanical Hanna arcitome (Moria, Antony, France) compared with those of femtosecond laser arcuate keratotomy. They determined that the high-tech approach was favorable. “The femtosecond laser arcuate keratotomy was much more predictable and had slightly better results,” Dr. Channa said. “The accuracy of the depth and placement of the incisions was much better when it was guided by the femtosecond laser.” She stressed, however, that the numbers were small. Yet another option considered in the review was the use of intraocular lenses. Some of the studies looked at corneal transplant patients who had undergone cataract surgery with combined intraocular lens placement. Also under consideration was the use of phakic and piggyback IOLs with full correction of astigmatism. “There was a study that found that IOLs are a better option when you do a piggyback IOL rather than when you do a refractive lens exchange because some of these IOLs may be in for a longer time,” Dr. Channa said. “The Artisan toric IOL [Ophtec, Groningen, the Netherlands] implanted in one reported series decreased astigmatism 88% and corrected an average of 5 D of astigmatism.” Overall, Dr. Channa sees the issue of using refractive surgery to correct astigmatism and spherical error in these transplant patients as an important one. “The facts are that we’re left with patients following PK and we have to determine what to do when we get these refractive surprises,” she said. “You may have a successful graft in terms of having a clear graft, but we need to address the patient’s visual rehabilitation.” Even newer deep anterior lamellar keratoplasty (DALK) and Descemet’s- stripping endothelial keratoplasty (DSEK) surgeries are not immune to these problems. “There are some case reports of PRK for DALK patients and they are doing arcuate incisions for patients who end up with high astigmatism following deep anterior lamellar keratoplasty,” Dr. Channa said. “I’m sure this would also be such for patients who are undergoing DSEK.” EW Editors’ note: Dr. Channa has no financial interests related to her comments. Contact information Channa: pchanna@montefiore.org