EyeWorld Asia-Pacific December 2013 Issue

30 EWAP rEfrActivE December 2013 Corneal - from page 29 keratoplasty) and DSAEK (Descemet’s stripping automated endothelial keratoplasty),” Dr. Sutphin said. “The tissue still has value.” Dr. Terry, who developed the endothelial keratoplasty technique here in the U.S., is the one who originally urged the medical advisory board to update the eye bank rules on this. “What I recommended was that they change the rules restricting these prior refractive surgery donors from use in ‘corneal transplantation’ so that these tissues would be allowed for endothelial keratoplasty. By changing the old rules, we could then transplant the healthy back part of the cornea and utilize all of these tissues that were coming in with LASIK and PRK,” he said. He subsequently published two papers showing that there is no difference in the results of using corneas from a donor with previous LASIK, PRK, or even RK, when this is used for DLEK (deep lamellar endothelial keratoplasty), DSEK (Descemet’s stripping endothelial keratoplasty), and DMEK. 1,2 Still, some adaptation may be needed. With prior refractive tissue, the preparation may be a bit different, Dr. Sutphin noted. “It is best if you know they’ve had LASIK because you would adjust the parameters that you use to prepare the tissue,” he said. “The cornea will be thinner so you may need to use a different kind of device or different depth of device in making the cuts.” Also, he said the original LASIK flap might slip while you’re trying to prepare the button to be used for DSEK or DMEK. Dr. Glasser said it is up to eye bank medical directors to determine whether they will use previous refractive surgery tissue. “That’s a bank-by-bank and ultimately a surgeon-by-surgeon decision,” he said. “I personally wouldn’t hesitate to take tissue from a patient who previously had LASIK and use it for endothelial keratoplasty, but some surgeons would.” Some have concerns as to whether the endothelial cells are OK, but he feels that’s not supported by evidence. There’s also a question as to whether this will have a refractive result on the recipient. “Theoretically if you’re transplanting endothelium, Descemet’s and 75 to 150 microns of stroma, if that graft is a little thicker or a little thinner at the edges than it is at the center, it might have a refractive effect,” Dr. Glasser said. He said that gone are the days when it was OK to have a large refractive surprise following corneal transplant. With a standard EK graft there is only about a 1.5 D hyperopic shift. EK, Dr. Glasser noted, has taken over the dominant keratoplasty procedure as of 2012, for the first time surpassing the number of penetrating keratoplasties done. While there is an increased chance of unpredictable refractive results from prior refractive tissue with DSEK, Dr. Himmel said this isn’t an issue with DMEK. “You don’t have any stroma for DMEK so there’s no worry about odd refractive outcomes in those situations,” he said. “It’s conceivable that even the 300 tissues that were rejected last year for having had refractive surgery could have been used for DMEK.” Overall, Dr. Terry thinks that it is fortunate that LASIK and other refractive donors can now be utilized. In the future, he said patients will be able to undergo transplantation of tissue that is the product of crosslinking or with Intacs (Addition Technology, Des Plaines, Ill., USA) or inlays inside the cornea, among other things. “The information we have to get out to the public is that if they had LASIK, a presbyopic inlay, or other procedures that leave healthy endothelium, they can be donors,” Dr. Terry said. EWAP references 1. Phillips PM, Terry MA, Shamie N, Chen ES, Hoar KL, Stoeger C, Friend DJ, Saad HA. Descemet’s stripping automated endothelial keratoplasty (DSAEK) using corneal donor tissue not acceptable for use in penetrating keratoplasty due to anterior stromal scars, pterygia, and previous corneal refractive surgeries. Cornea 2009;28:871-6. 2. Armour RL, Ousley PJ, Wall J, Hoar KL, Stoeger C, Terry MA. Endothelial keratoplasty using donor tissue not suitable for full-thickness penetrating keratoplasty. Cornea 2007;26:515-519. Editors’ note: The physicians have no financial interests related to this article. contact information Glasser: +1-443-283-8800, dbg@comcast.net Himmel: +1-505-888-5757, khimmel@eyenm.com Sutphin: +1-913-588-6600, jsutphin@kumc.edu terry: +1-503-413-6223, mterry@deverseye.org descriptive, the reader should realize that IOL is just as non- descriptive to the average patient. Does a “premium widget” sound better to you then a “standard widget?” Probably not. You cannot infer any benefit from the name alone; however, from the name alone you can probably infer that the “premium” widget is more expensive. This brings us to the current evolution for the name of lenses in the PC-IOL category: “advanced technology IOLs.” Going back to our widget analogy, which would you rather have, an “advanced technology widget” or a “standard widget”? It’s clear from the wording alone that something about the widget with the advanced technology is better than a standard widget. Does the name itself confer anything about price or cost? Not in the same pejorative way that “luxury” or “premium” imply additional expense. However in terms of the heuristics of “categorizing” the listener puts the “advanced technology widget” into the category of a better product, and past experience leads to the common observation that better products usually cost most. When you think about the above, the evolution of nomenclature for the PC-IOLs from elective to premium to advanced technology is understandable. At present, advanced technology IOL seems preferable to the other terms previously utilized, as it can help patients understand the potential benefits of PC-IOL technology without having any negative implications regarding cost. EWAP Editors’ note: Dr. Tipperman is affiliated with the Wills Eye Institute, Philadelphia, Pa., USA. contact information tipperman: rtipperman@mindspring.com A rose - from page 24