Possible Predisposing Factors for In-the-Bag and Out-of-the-Bag Intraocular Lens Dislocation and Outcomes of Intraocular Lens Exchange Surgery Ken Hayashi, MD, 1 Akira Hirata, MD, 1,2 Hideyuki Hayashi, MD 3 Objectives: To examine the possible predisposing factors for intraocular lens (IOL) dislocation within the capsular bag (in-the-bag dislocation) and IOL dislocation outside of the capsule (out-of-the-bag dislocation) and to study surgical outcomes of explantation of dislocated IOLs and scleral suturing of posterior chamber IOLs. Design: Retrospective interventional case series. Participants: Thirty-eight eyes of 38 patients who developed in-the-bag IOL dislocation and 24 eyes of 24 patients who experienced out-of-the-bag dislocation. Intervention: Medical records of 62 consecutive patients who underwent IOL exchange surgery for dislo- cation between 1999 and 2005 were reviewed. Main Outcome Measures: Possible predisposing factors and the other characteristics of in-the-bag and out-of-the-bag IOL dislocations; outcomes of IOL exchange surgery, including visual acuity (VA) and refractive status before and at 12 months after surgery; and serious postoperative complications. Results: Possible major predisposing factors for in-the-bag IOL dislocation were pseudoexfoliation (17/38 [44.7%]), retinitis pigmentosa (4/38 [10.5%]), the status after vitrectomy (2/38 [5.3%]), trauma (2/38 [5.3%]), and a long axis (2/38 [5.3%]), whereas those for out-of-the-bag dislocation were secondary IOL implantation (11/24 [45.8%]), surgical complications (3/24 [12.5%]), mature cataract (3/24 [12.5%]), and pseudoexfoliation (2/24 [8.3%]). The interval between IOL implantation and exchange surgery was significantly shorter for the in-the-bag dislocation group than for the out-of-the-bag dislocation group (P = 0.0006). Mean uncorrected VA improved significantly after IOL exchange (P = 0.0080), and corrected VA also tended to improve, although the improve- ment was not significant (P = 0.0704). Mean absolute value of spherical power decreased significantly after surgery (P = 0.0008), whereas refractive astigmatism showed a significant increase (P = 0.0003). The primary serious complications after surgery were a marked rise in intraocular pressure (12/62, 19.4%), retinal detachment (4/62, 6.5%), and redislocation (2/62, 3.2%). Conclusions: Possible major predisposing factors for in-the-bag IOL dislocation are pseudoexfoliation, retinitis pigmentosa, the status after vitrectomy, and trauma, whereas those for out-of-the-bag dislocation are secondary implantation, surgical complications, and mature cataract. After IOL exchange surgery, corrected VA does not improve markedly. Because the incidence of postoperative complications after IOL exchange with scleral suturing is high, the use of other surgical techniques should be considered. Ophthalmology 2007;114: 969 –975 © 2007 by the American Academy of Ophthalmology. Dislocation of an intraocular lens (IOL) is one of the most serious complications after cataract extraction (CE) and IOL implantation. Many previous studies reported that the incidence of dislocation of posterior chamber (PC) IOLs ranged from approximately 0.2% to 2%. 1–6 Until the 1980s, dislocation of the IOL usually occurred outside of the capsule, and was often referred to as the sunset or sunrise syndrome. 7,8 It has been suggested that this out-of-the bag dislocation is predominantly due to asymmetrical fixation of the IOL or to complicated sur- Originally received: May 10, 2006. Accepted: September 25, 2006. Manuscript no. 2006-516. 1 Hayashi Eye Hospital, Fukuoka, Japan. 2 Department of Ophthalmology, Saga University Faculty of Medicine, Saga, Japan. 3 Department of Ophthalmology, School of Medicine, Fukuoka University, Fukuoka, Japan. The authors have no proprietary interest in any of the materials described in the article. Correspondence and reprints requests to Ken Hayashi, MD, Hayashi Eye Hospital, 4-7-13 Hakataekimae, Hakata-ku, Fukuoka 812-0011, Japan. E-mail: hayashi-ken@hayashi.or.jp. 969 © 2007 by the American Academy of Ophthalmology ISSN 0161-6420/07/$–see front matter Published by Elsevier Inc. doi:10.1016/j.ophtha.2006.09.017