MAR 2014

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

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E W CORNEA 98 March 2014 When corneal edema emerges among patients with AC IOLs, the best surgical approach may or may not include removal of the lens N ew research has heated up the discussion of w hether surgical treat- ments for corneal edema among anterior chamber (AC) IOL recipients should include removal of the lenses. A comparative case series pub- lished in the December 2013 issue of the Journal of Cataract & Refractive Surgery found that bullous keratopa- thy treatment in eyes with AC IOLs was feasible with Descemet's membrane endothelial keratoplasty (DMEK) surgery. Additionally, the researchers found IOL removal may be required if postop complications were anticipated but it did not facili- tate either thin Descemet's stripping endothelial keratoplasty (thin-DSEK) or DMEK. The study also concluded the surgical approach may minimize postop complications by using thin-DSEK in eyes with low visual potential or concomitant pathology and DMEK in eyes with a phakic AC IOL and normal visual potential. Mark A. Terry, MD, director of the corneal services, Devers Eye Institute, and professor of clinical ophthalmology, Oregon Health & Science University, Portland, ques- tioned the finding that it is possible to get a successful DMEK in such eyes and leave low lying type AC IOLs in place. The problem, he said, is that the approach tremendously increased the percentage of endothe- lial damage and cell loss over stan- dard DMEK or DSAEK, and the rebubble rate was "quite high." "For now, I am not advising surgeons to perform DMEK in eyes with an AC IOL left in place, and even if the AC IOL is replaced with a posterior chamber IOL, the DMEK surgery is much more difficult to perform than standard DMEK in simple Fuchs' corneal dystrophy eyes," Dr. Terry said. If patients have glaucoma, peripheral anterior synechiae and marginal IOP control, D. Brian Kim, MD, in private practice, Dalton, Ga., is inclined to exchange the AC IOL. However, patients with compli- cated corneal disease and posterior/ endothelial dysfunction or those with anterior corneal disease in the form of corneal scarring or a degen- erative condition like keratoconus leads Dr. Kim to consider a full thickness approach with penetrating keratoplasty. "Although I try to perform DSAEK whenever possible, some- times it's better to go with a full thickness procedure," Dr. Kim said. "We mustn't dismiss this in our decision algorithm." Dr. Terry said other risks of re- moving a scarred-in AC IOL include bleeding and iris tears. Additionally, replacing an AC IOL with a posterior chamber IOL can add significant time to the transplant surgery and bring additional risks. Initial approaches The approach Dr. Terry takes to AC IOL cases includes first assessing if the AC IOL is stable and second if the AC IOL is causing continuous damage to the endothelium, which would necessitate removal. "If the AC IOL is stable and the corneal decompensation that we see is simply a result of the original traumatic surgery and years of endothelial loss over time, the IOL can be left in place," Dr. Terry said. "In other words, if the patient had good vision for 15 or 20 years with the AC IOL in place, and only re- cently had corneal edema, then we simply do a DSAEK and leave the AC IOL in place." If the AC IOL was recently placed and the cornea decompen- sated—especially if the IOL is tilted or unstable—then he replaces the AC IOL with a posterior chamber I OL and performs DSAEK. If there are no other anterior segment abnor- malities, DMEK surgery with the replacement posterior IOL in place can be considered, he said. Woodford S. Van Meter, MD, professor of ophthalmology, Univer- sity of Kentucky, and medical direc- tor, Lions Eye Bank, Lexington, Ky., s aid another main reason for IOL exchange is that changes in the corneal curvature can affect the power of the IOL. "Anytime you change the corneal refracting power with a ker- atoplasty procedure, you may also need to change the IOL to maintain emmetropia or maintain the existing r efracting power of the eye," Dr. Van Meter said. For example, in penetrating graft patients who had a previously implanted AC IOL based on a signif- icantly steeper or flatter cornea, Dr. Van Meter replaces the IOL because he knows what his average postop corneal curvature will be. Pearls underscored To minimize postop complications, Dr. Terry said the first priority should always be to minimize donor endothelial damage at the time of surgery. This is achieved by ensuring that the donor endothelium does not come into contact with the plastic surface of the AC IOL. "To position and unfold the graft, push down on the AC IOL while injecting balanced salt solu- tion to start the unfolding, then also push down on the IOL while inject- ing the air to finish off the unfold- ing," Dr. Terry said. EW Reference Liarakos VS, Ham L, Dapena I, Tong CM, Quilendrino R, Yeh RY, Melles GR. Endothelial keratoplasty for bullous keratopathy in eyes with an anterior chamber intraocular lens. J Cataract Refract Surg. 2013 Dec;39(12): 1835-45. Editors' note: Drs. Van Meter and Kim have no financial interests related to this article. Dr. Terry has financial in- terests with Bausch + Lomb (Rochester, N.Y.) and Moria (Antony, France). Contact information Terry: mterry@deverseye.org Kim: kim@professionaleye.com Van Meter: wsvanmeter@aol.com by Rich Daly EyeWorld Contributing Writer Corneal edema affects fate of AC IOLs DSAEK done seven years ago with an AC IOL in place and vision of 20/20 Source: Mark A. Terry, MD 88-107 Cornea_EW March 2014-DL2_Layout 1 3/6/14 3:47 PM Page 98

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