Changes in intraocular lens position after neodymium : YAG capsulotomy

Purpose: To quantify changes in intraocular lens (IOL) position caused by n eodymium: YAG (Nd:YAG) capsulotomy with 3 IOL styles. Setting: Department of Ophthalmology, University of Vienna, Austria. Methods: In a prospective study, anterior chamber depth (ACD) was measured by dual-beam partial coherence interferometry (PCI) in 32 pseudophakic eyes of 32 patients with posterior capsule opacification before and immediately after planned capsulotomy under mydriasis. Patients were divided into 3 gr oups with the following IOL styles: 1- piece poly(methyl methacrylate) (PMM A), 3-piece foldable, and plate haptic. Results: The capsulotomy induced a backward IOL movement in all 32 eyes (me an 25 mu m; range 9 to 55 mu m). It was more pronounced in eyes with plate- haptic IOLs than in those with the other styles. Precision of ACD measureme nt by PCI was 4 mu m. Changes in ACD correlated significantly with capsulot omy size but not with preoperative lens-capsule distance. Conclusion: Capsulotomy caused a backward movement of the IOL, which was mo re pronounced with plate-haptic IOLs than with 1-piece PMMA and 3-piece fol dable IOLs. Since the magnitude of IOL movement in this study population wa s small, a hyperopic shift in refraction after capsulotomy will usually be small and not clinically relevant. J Cataract Refract Surg 1999; 25:659-662 (C) 1999 ASCRS and ESCRS.