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EW CORNEA November 2010 23 amination, the misidentification rate decreased to 3.4% (2 of 59)." The difference in misidentifica- tion was significant only between groups 2 and 3, which emphasizes the importance of taking a donor history to detect corneas with previ- ous LASIK, Dr. Grossniklaus noted. Potential reasons for mislabeling corneas include the time between donor death and preservation, unde- tectable flap edges during slitlamp investigation, misdiagnosis of the condition of the eye (the patient could have had arcus senilis, for ex- ample), and inaccurate patient his- tory, Dr. Grossniklaus suggested. "In our study, we found that eye banks sometimes considered both eyes as 1 group, so if the screening method, especially the medical his- tory, was incorrect, both corneas were not used as donors even though the LASIK had been per- formed in only 1 eye," Dr. Gross- niklaus reported. Dr. Grossniklaus stopped short of recommending more high-tech ways of determining previous refrac- tive surgery in donor corneas. "Spec- ular microscopy, topographic analysis, computerized videoker- atometry, darkfield biomicrography, and optical coherent tomography, have been proposed as a new screen- ing method to detect post-LASIK corneas," Dr. Grossniklaus reported. "However, these require high-cost instruments, and each method has its own sensitivity and specificity de- pending on the nature of the refrac- tive procedure, such as the status of the corneal epithelium, or the feasi- bility for examination of whole globe versus corneoscleral prepara- tions." It's worthwhile to find a way of correct corneal identification, how- ever, as one example in the study demonstrated how a perfectly healthy cornea was deemed unsuit- able as a transplant. "The corneas from a 65-year-old female were identified by an eye bank as having previous LASIK sur- gery," Dr. Grossniklaus reported. "The corneoscleral specimen was procured 7 hours and 50 minutes after death and preserved in Optisol [Bausch & Lomb, Rochester, N.Y.]. The slit-lamp examination showed a semicircular line, so the eye bank re- jected them for transplantation. His- tologic examination showed a normal cornea with no evidence of previous surgical wound." Mark Packer, M.D., clinical as- sociate professor of ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Ore., said it's amazing that so many donor corneas are being misidentified. "That's so interesting," said Dr. Packer, who mentioned that it can indeed be difficult distinguishing which corneas have had LASIK. "There may be more than 10% of corneas where I can't see the edge of a LASIK flap" at the slitlamp, Dr. Packer said. "A year or more [after surgery], I sometimes have a very hard time finding the edge of the flap." Dr. Packer agreed that taking an accurate patient history should help identify more corneas correctly. "I wonder if they should be doing to- pography on these eyes, not that it would give you 100% [correct identi- fication]," Dr. Packer said. "Prior to removing the cornea, they could get a topography map." EW Editors' note: Dr. Grossniklaus has no financial interests related to this study. Dr. Packer has no financial interests re- lated to his comments. Contact information Grossniklaus: ophtheg@emory.edu Packer: 541-687-2110, mpacker@finemd.com for your practice Integrated solutions Ziemer Ophthalmic Systems AG (International) Allmendstrasse 11, 2562 Port, Switzerland Phone +41 32 332 70 50 Fax +41 32 332 70 70 e-mail innovation @ ziemergroup.com Ziemer USA, Inc. (United States) 321 Ridge Street, Alton, IL 62002, USA Phone +1 618-462-9301 toll-free 866-708-4490 e-mail usa @ ziemergroup.com www.ziemergroup.com Dual Scheimpflug Analyzer by Ziemer Advanced Automated Microkeratome Dynamic Contour Tonometer Femtosecond Surgical Laser egr t In ou y or f o s d e t a egr ce i t c a r p r ou s n o i t u l o ce Solutions Solutions Femtosecond Surgical Laser Solutions Femtosecond Surgical Laser Microkeratome Advanced Automated Dynamic Contour Tonometer Advanced Automated ziemergroup.com @ e-mail innovation 32 332 70 50 Fax + 1 4 Phone + , 2562 Port, Switzerland 1 1 Allmendstrasse Ziemer Ophthalmic Systems AG Solutions Solutions by Ziemer ziemergroup.com @ e-mail usa 8-462 1 6 Phone +1 Ridge Street, Alton, IL 62002, USA 1 32 Ziemer USA, Inc. ziemergroup.com 32 332 70 70 1 4 32 332 70 50 Fax + , 2562 Port, Switzerland ) International ( Ziemer Ophthalmic Systems AG Solutions by Ziemer www.ziemergroup.com ziemergroup.com 08-4490 7 1 toll-free 866- -930 8-462 Ridge Street, Alton, IL 62002, USA (United States) Ziemer USA, Inc. www.ziemergroup.com

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