Purpose: To investigate the axial movement in the first postoperative week and the influence of capsular bag size with an angulated, 3-piece, open-loop, acrylic intraocular lens (IOL). Setting: Department of Ophthalmology, Medical University of Vienna, Vienna, Austria. Methods: Twenty-nine eyes of 29 patients with age-related cataract were included in this study. In study 1, an open-loop, 3-piece IOL (AR40e, AMO) was implanted in a standardized fashion in 15 eyes of 15 patients' In study 2, before IOL implantation, a capsular tension ring (CTR) was inserted (14 eyes of 14 patients). Anterior chamber depth (ACD) was assessed with partial coherence interferometry 2 hours; 1, 3, and 5 days; 1 week; and 1 month postoperatively. The capsular bag diameter (CBD) was assessed using gonioscopic measurement of the eyelets of the CTR 1 day, 1 week, and 1 month postoperatively. Results: In the first postoperative week, there was a significant mean forward movement of -196 mu m +/- 117 (SD) (P <.005) in study 1 and -139 +/- 97 mu m in study 2 (P <.005). These movements correspond to refractive changes of -0.31 diopter (D) and -0.20 D, respectively. The movement was linear in the first 5 days after surgery. Different patterns of early postoperative movement were seen, illustrating interindividual variability. A significant correlation of 0.67 (P <.05) was found between the change in ACD and CBD. Conclusions: A linear forward movement of the IOL during the first postoperative week was followed by a relatively stable IOL position. Loss of haptic memory seemed to be the most likely cause. Myopic eyes with large capsular bags showed less IOL shift in the early postoperative period than hyperopic eyes with smaller capsular bags. (c) 2005 ASCRS and ESCRS.