EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/111385
42 EW CATARACT February 2013 A new complication after endothelial keratoplasty procedures by Vanessa Caceres EyeWorld Contributing Writer Opaci���cation, calci���cation linked to a certain type of IOL material S urgeons may want to avoid hydrophilic acrylic lenses when performing cataract surgery either concurrently or in a patient at risk for an endothelial keratoplasty procedure, a number of fellow surgeons are reporting. That��s because these surgeons are finding they have to explant the IOLs after IOL calcification forms right where the visual axis and air bubble were in contact, causing opacification and essentially decreasing a patient��s vision, said W. Barry Lee, M.D., Cornea, External Disease, & Refractive Surgery, Eye Consultants of Atlanta/ Piedmont Hospital, Atlanta. ��It��s clear that the air bubble is reacting to the hydrophilic acrylic lens material and causing a buildup of hydroxyapatite. Over time it gets more opacified and eventually leads to a drop in vision,�� Dr. Lee said. ��The problem is its directly in the patient��s central vision so we very likely have to do a lens explant, which is risky for the endothelial transplant survival.�� Tracking the problem Opacified Memory Lens after DSAEK Opacified Rayner IOL after DSAEK. After dilation, the hydroxyapatite respects the visual axis and only coats the anterior surface of the IOL where the previously undilated pupil was present. The iris protected the remainder of the IOL from opacification. Source (all): W. Barry Lee, M.D. This is a new problem related to endothelial keratoplasty procedures as this kind of surgery has only been around a few years, Dr. Lee said. However, calcification of some hydrophilic IOLs previously occurred one to two years after cataract surgery, said Nick Mamalis, M.D., professor of ophthalmology, John A. Moran Eye Center, Department of Ophthalmology & Visual Sciences, University of Utah, Salt Lake City. The calcification in those cases occurred in different locations and for different reasons. Surgeons rarely if ever have seen that kind of calcification with modern hydrophilic IOLs until the localized calcification after Descemet��s stripping endothelial keratoplasty (DSEK) or Descemet��s stripping automated endothelial keratoplasty (DSAEK) began to occur, he said. Although Dr. Lee said there are few published reports on this problem right now, he said there is even more word-of-mouth evidence from surgeons that this problem is occurring more often. Additionally, a report of three cases in the October 2012 issue of Cornea by Patryn et al. as well as a letter in the April 2012 issue of the Journal of Cataract & Refractive Surgery (JCRS) from Werner et al. have addressed the problem. ��We have recently published a letter calling attention to a phenomenon of calcification of intraocular lenses following procedures using intracameral injections of air or gas, including posterior lamellar keratoplasty techniques,�� said Liliana Werner, M.D., associate professor and co-director, Intermountain Ocular Research Center, Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, referring to the JCRS letter. ��Since that publication, we have received new specimens in our laboratory at the John A. Moran Eye Center represented by lenses calcified after DSEK or DSAEK.�� The exact cause and how often the problem is occurring are not yet clear, Dr. Mamalis said. ��Something is changing on the anterior surface of the IOL. We��re trying to figure out what it is,�� he said. The problem does not seem to be linked with IOLs from a particular manufacturer, Dr. Werner said. All lenses studied by Dr. Werner and co-investigators have a distinctive pattern of calcification localized to the anterior surface/subsurface of the lens and within the pupillary or the capsulorhexis area. ��The calcification was very dense and could not be removed by Nd:YAG laser applications or surgical means, and the lenses had to be explanted due to decrease in visual function,�� Dr. Werner said. Dr. Werner��s letter discusses the circumstances surrounding the handful of reported cases where this problem has occurred. One such case analyzed at her lab had localized IOL calcification after DSAEK. In June 2010, the patient had Fuchs�� dystrophy and phacoemulsification, followed by hydrophilic IOL implantation. The DSAEK procedure was performed with intracameral injections of air in October 2010. ��Two months later, the patient complained of ��foggy�� vision,�� Dr. Werner and co-investigators reported. ��Opacification of the anterior surface of the IOL within the pupillary area was observed. As Nd:YAG laser disruption of the opacification was not successful, surgeons exchanged the IOL in October 2011.�� Implications The easiest way to prevent this problem is to avoid hydrophilic acrylic lenses in patients where cataract surgery is needed concurrently or prior to DSEK or DSAEK. Surgeons should instead use hydrophobic lenses in those patients. ��For the moment, surgeons should consider avoiding hydrophilic acrylic IOLs when procedures using intracameral air or gas are anticipated, particularly in DSEK or DSAEK,�� Dr. Werner said. Generally speaking, surgeons in Europe use hydrophilic lenses more often, said Dr. Mamalis. However, even surgeons in the U.S. may have their personal preferences for the material, Dr. Lee said. In Dr. Lee��s office, some surgeons favor the use of hydrophilic acrylic lenses in routine cataract cases, and they work great in most cases��except for in two patients in whom the hydrophilic acrylic IOLs had to be explanted after endothelial keratoplasty procedures due to severe opacification and vision decline. In both cases the DSAEK was performed for advanced Fuchs�� dystrophy following prior cataract surgery. The IOL explantation occurred with the first year after the DSAEK procedures. IOL explantation under an endothelial graft carries a high risk for potential endothelial graft damage. ��If a patient is going to have combined DSAEK and cataract removal, or if it is a patient with Fuchs�� dystrophy and you see moderate to advanced guttata, avoid hydrophilic acrylic lenses in those cases,�� Dr. Lee said. ��This is another thing to think about when you see patients with Fuchs�� dystrophy to avoid a potential serious complication.�� However, this area requires further research, Dr. Werner believes. ��Further investigation in this phenomenon is necessary to ascertain if the localized calcification is a result of direct contact between the IOL surface and the exogenous gas and air, of a metabolic change in the anterior chamber due to the presence of the exogenous gas and air, or the result of an exacerbated inflammatory reaction after multiple surgical procedures,�� said Dr. Werner. EW Editors��� note: The physicians have no financial interests related to this article. Contact information Lee: 404-351-2220, lee0003@aol.com Mamalis: 801-581-6586, nick.mamalis@hsc.utah.edu Werner: 801-581-8136, liliana.werner@hsc.utah.edu