EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/511377
EW RESIDENTS 62 May 2015 by Dipika Joshi, MD, Andrew Kao, MD, Natasha Nayak, MD, Andrew Nightingale, MD, Nicole Scripsema, MD, and Anita Gupta, MD D espite advances in cataract surgery, postop complica- tions persist. In-the-bag intraocular lens (IOL) subluxation or dislocation is a noted late postop complication of cataract surgery. The etiologies for this late complication have been found to arise from conditions that result in zonular instability. Re- ported causes of zonular weakness include pseudoexfoliation syndrome (PXF), trauma, and connective tissue disorders. Numerous histopathologic stud- ies implicate PXF as one of the most predominant factors related to zonu- lar instability. 1,2,3 PXF is a systemic disease in which a matrix of fibrotic material is deposited throughout the body. In the eye, a periodic acid- Unexpected late bag-IOL dislocation due to pseudoexfoliation disappoints patients and challenges surgeons. This month, I asked the New York Eye and Ear Infirma y residents to review this large CPC series from the University of Utah's Moran Eye Center. –David F. Chang, MD, EyeWorld journal club editor Schiff (PAS) positive fibrillogranular white material is deposited on struc- tures throughout the anterior seg- ment, most notably the lens capsule and zonular fibers. While controve - sial, various studies have suggested a higher prevalence of PXF in patients of Scandinavian descent. 4,5 Variants of lysyl oxidase-like 1 (LOX-L1), a protein implicated in elastin metabolism, are associated with the inheritance of PXF. 6 Clinical signs of PXF syndrome include iris atrophy at the pupillary margin ("moth-eat- en" pupillary ruff), deposition of PXF material on the anterior lens capsule, poor pupillary dilation, increased pigmentation of the tra- becular meshwork, and secondary open-angle glaucoma. Deposition of PXF material on the zonular fibers leads to an increased risk of zonular dehiscence, intraoperative vitreous loss, and late postoperative IOL sub- luxation or dislocation. 7 In the May issue of the Journal of Cataract & Refractive Surgery, Liu and colleagues assessed the presence of pseudoexfoliation material in explanted capsular bags containing intraocular lens implants with or without capsular tension rings that had spontaneously subluxated or dislocated in the late postop period. In this retrospective case series, 40 consecutive explantation specimens were submitted over an 18-month period to the John A. Moran Eye Center, University of Utah, by 2 sur- geons at the University of Frankfurt. Pathologic evaluation consisted of gross examination, light microscopy analysis, and histopathologic eval- uation. After standard processing, the 3 µm sections of the explant- ed specimens were stained with Masson's trichrome. One observer masked to the clinical diagnosis of PXF then analyzed the specimens for the presence or absence of PXF, which was suggested by an amor- phous material on the outer surface of the lens capsule in an "iron-fi - ing" pattern. Preoperative clinical diagnosis of PXF for all patients was determined by reviewing submitted surgeon questionnaires regarding the patients' clinical data. Patients' charts were also reviewed, when available, to complete and confirm clinical data. Of the 40 specimens submitted, 37 capsular bags contained an IOL and the remaining 3 contained both an IOL and capsular tension ring (CTR). A wide range of IOL designs were represented in this study, including both 1-piece and 3-piece lenses, as well as silicone, hydro- phobic and hydrophilic acrylic, and PMMA lenses. A majority (65%) of specimens were obtained from females. The mean age range of patients at time of explantation was 77.1 ±10.0 years. On average, ex- plantation was performed 12.0±4.8 years after implantation. Patients underwent explantation due to either dislocation (95%, n=38) or subluxation (5%, n=2). Comorbid ocular conditions included PXF and glaucoma, previous vitrectomy or other surgery, myopia, retinitis pigmentosa, Marfan syndrome, and history of trauma. Capsular phimosis was seen in 24 specimens. Histopathologic evidence of PXF was identified in 65% of specimens (n=26), although only 50% of those specimens had a clinical history of PXF (n=13). Of the 14 specimens with no histopathologic evidence of PXF, 10 specimens had other identifiable risk factors for zonular instability. Additionally, of the 24 specimens with capsular phimosis, 17 had histopathologic evidence of PXF. Liu et al show in their study that half of explanted specimens with histopathologic evidence of PXF were not identified as having PXF on preop clinical evaluation. This raises the concern that a large proportion of PXF is subclinical or difficult to diagnose, even when considering risk factors for the condition such as gender and ethnicity. The classic signs of PXF clearly do not encom- pass all patients with the condition, and earlier and more subtle signs of PXF should be considered during the preop evaluation. Ritch et al proposed the presence of a pre-cap- sular and later a pre-granular stage that may represent very early stages of PXF. 8 The pre-capsular stage was described as a homogeneous ground- glass or matte appearance of the lens surface in one eye compared to the other. In the proposed slightly later pre-granular stage, the presence of 80 faint, radial, non-granular striae may be seen on the mid-third of the anterior capsule behind the iris. In the future, more objective tech- niques to supplement the slit lamp examination such as serologic or Review of "Pathological evidence of cases of in-the-bag intraocular lens Pathological evidence of pseudoexfoliation in cases of in-the-bag intraocular lens subluxation or dislocation Erica Liu, MD, Scott Cole, MD, MS, Liliana Werner, MD, PhD, Fritz Hengerer, MD, Nick Mamalis, MD, Thomas Kohnen, MD, PhD, FEBO J Cataract Refract Surg (May) 2015;41:Article in press Purpose: To provide complete histopathological evaluation of explanted capsular bags that spontaneously dislocated in the late postoperative period, with the main objective to assess the presence of pseudoexfoliation (PXF) material. Setting: Goethe-University Frankfurt, Germany, and John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. Design: Retrospective case series. Methods: Forty explanted subluxated and dislocated capsular bags containing an intraocular lens (IOL) or a capsular tension ring (CTR) and an IOL had standard gross and light microscopy and complete histopathology. Questionnaires were sent to explanting surgeons and patient chart review was performed, when available. Results: The specimens were represented by capsular bags containing an IOL (N=37) or an IOL–CTR (N=3). The IOLs included 3-piece hydrophobic acrylic (N=13), 1-piece hydrophobic acrylic (N=7), 3-piece silicone (N=6), 1-piece hydrophilic acrylic (N=6), 3-piece hydrophilic acrylic (N=2), and 1-piece poly(methyl methacrylate) (PMMA) (N=6) designs; all CTRs were made of PMMA. Eight specimens exhibited mild Soemmering ring formation, 18 exhibited moderate Soemmering ring formation, 14 exhibited severe Soemmering ring formation. Excessive contraction of the capsular bag with capsulorhexis phimosis was observed in 24 specimens. Twenty-six specimens had histopathological evidence of PXF, while only 13 had a clinical history or evidence of PXF. Conclusions: Pseudoexfoliation may be implicated in a larger proportion of late in-the-bag IOL subluxations and dislocations than previously thought due to significant clinical under diagnosi . This may impart a need for new considerations during the preoperative and postoperative cataract surgery assessments and follow-up. Financial Disclosure: No author has a financial or proprieta y interest in any material or method mentioned. Anita Gupta, MD, residency program director, Department of Ophthalmology, New York Eye and Ear Infi mary of Mount Sinai EyeWorld journal club