EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
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September 2013 EW CATARACT 27 Cataract/IOL complications: Moran CPC reports A case of postoperative opacification of a hydrophilic acrylic IOL after DSAEK by Anne Floyd, MD, Liliana Werner, MD, PhD, Nick Mamalis, MD Anne Floyd, MD T he complication described in this article is related to a process of calcification occurring after certain corneal procedures. This phenomenon has been recently described by us and others in the peer-reviewed literature. Case report A 60-year-old female patient with a history of Fuchs' endothelial dystrophy had uneventful phacoemulsification with hydrophilic acrylic intraocular lens (IOL) implantation in OD in June 2010. Four months later she had Descemet's stripping automated endothelial keratoplasty (DSAEK) with intracameral injections of air. The patient presented two months later with "foggy" vision. Best corrected visual acuity was 20/60 in OD. Slit lamp examination demonstrated opacification of the anterior surface of the IOL within the pupillary area. The pupil in this eye was eccentric, which matched the central/paracentral area of opacification of the anterior IOL surface/ subsurface (Figure 1A). Attempted neodymium:YAG (Nd:YAG) laser disruption of the opacification was unsuccessful in clearing the opacity so the IOL was exchanged in October 2011. Nick Mamalis, MD Laboratorial analyses and results The explanted IOL was submitted to our laboratory for analysis. Gross examination showed a single-piece posterior chamber hydrophilic acrylic IOL with four closed-loop haptic components, which had been bisected for explantation. An offcentered, opaque discoloration was seen on the anterior surface of the IOL optic corresponding to the haze/opacification described clinically (Figure 1B and 1C). Microscopic examination of the lens revealed the presence of deposits densely distributed on the anterior surface/subsurface of the IOL and within the pupillary area. Multiple dark and irregular notches consistent with optic pits created by Nd:YAG laser treatment were present within the area of deposits. The deposits stained red with the 1% alizarin red stain, indicating they were composed at least in part of calcium (Figure 1D). Comments Dystrophic/primary calcification of some hydrophilic acrylic lenses is well described in the literature, and has been associated with factors such as IOL manufacture, IOL packaging, surgical techniques and adjuvants, as well as patient metabolic Liliana Werner, MD, PhD conditions, among others.1,2 However, there is an emerging phenomenon of secondary calcification of various hydrophilic acrylic IOLs following procedures, such as DSAEK and DSEK, that introduce air or gas into the anterior chamber through repeated injections.2-6 This secondary calcification occurs in a distinctive pattern, localized to the anterior surface/subsurface of the IOL and within the pupillary or capsulorhexis margins. Because of significant decrease in visual acuity, these IOLs are usually explanted and exchanged. Different reports have used various analytical techniques to evaluate the etiology of the opacification including histopathology, histochemistry, scanning electron microscopic examinations as well as elemental and molecular surface analyses.2-6 These evaluations have demonstrated that the opacification was related to calcium/phosphate precipitation on the surface/subsurface of the IOL optic, confined within the pupillary/capsulorhexis margins. We have already analyzed five cases in our laboratory, involving four different hydrophilic acrylic designs explanted after DSEK or DSAEK. The etiology of this type of secondary calcification of hydrophilic acrylic IOLs is still unclear. Addi- tional investigation is warranted to determine whether the localized calcification is a result of direct contact between the IOL surface and the exogenous air/gas or a metabolic change in the anterior chamber due to the presence of the exogenous air/gas, or the result of exacerbated inflammatory reaction after multiple surgical procedures/intracameral injections. It is important to be aware of this occurrence to increase surgeon clinical recognition and improve preoperative surgical planning. It may be beneficial to avoid the implantation of hydrophilic acrylic IOLs in patients who may be expected to require further surgical interventions involving exogenous air/gas adjuvants. Differential diagnosis 1. Posterior capsule opacification is observed behind the IOL and is caused by the proliferation and migration of residual lens epithelial cells along the posterior capsule. This is successfully treated with a posterior capsulotomy using an Nd:YAG laser. 2. Cell deposits, typically comprised of giant cells, macrophages and fibroblast-like cells, may adhere to the anterior surface of the IOL optic. Cell deposits typically resolve independently as they detach from the IOL surface postoperatively. EW References 1. Werner L. Calcification of hydrophilic acrylic intraocular lenses. Am J Ophthalmol 2008; 146:341–343. 2. Werner L. Causes of intraocular lens opacification or discoloration. J Cataract Refract Surg 2007; 33:713–726. 3. Dhital A, Spalton D, Goyal S, Werner L. Calcification in hydrophilic intraocular lenses continued on page 28 A B C D Figure 1: Clinical, gross, and light microscopy photographs of a case of localized hydrophilic acrylic IOL opacification (arrows) after DSAEK. The deposits on the anterior surface/ subsurface of the explanted lens stained positive for calcium (case of Garth Wilbanks, MD, Eastern Maine Eye Associates, Bangor, Maine). Source (all): Mamalis/Werner laboratory, Moran Eye Center