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Dynamic assessment of capsular bag stability: effect of a capsular tension ring in eyes with pseudoexfoliation syndrome during cataract surgery
Session Title: Imaging I
Session Date/Time: Sunday 06/10/2013 | 14:30-16:00
Paper Time: 14:36
Venue: Elicium 1 (First Floor)
First Author: : S.Maedel AUSTRIA
Co Author(s): : N. Hirnschall M. Weber J. Tabernero P. Artal O. Findl
To compare capsular bag stability in eyes with and without implantation of a capsular tension ring (CTR) and eyes with pseudoexfoliation syndrome (PXF) during cataract surgery using a dynamic Purkinje meter system.
Vienna Institute for Research in Ocular Surgery, Department of Ophthalmology, Hanusch Hospital, Vienna.
Intraoperative implantation of a CTR during cataract surgery may improve intracapsular IOL stability and reduce decentration and tilt. Also, eyes with PXF may have weak zonules, which can lead to reduced capsule bag stability. A novel dynamic Purkinje meter system allows measurement of the dangling or “wobbling” of an IOL by analyzing saccadic eye movements with simultaneous video recording of Purkinje reflexes. Lens or IOL wobbling can be quantified by terms of maximal wobbling amplitude (pixels) or maximal wobble time (msec), representing the time of oscillating of the IOL to return to its stationary position. Higher oscillation amplitudes and larger wobble time indicate a larger amount of lens/IOL wobbling. In this prospective, randomized clinical trial, 40 eyes of 20 patients were included. A bilateral comparison of IOL stability in eyes with and without implantation of a capsular tension ring was performed concerning IOL tilt, decentration and wobbling parameters. Additionally, 10 eyes of 10 patients with PXF were included to analyze former parameters of capsule bag stability. Measurements were performed in all eyes pre-operatively, 1 hour, 1 week and 3 months post-operatively.
Preliminary results include data of 18 eyes of 9 patients in the CTR comparison group and 4 eyes with PXF. 1 hour postOP, mean (SD) wobble amplitude and wobble time for eyes with and without a CTR were 38.9 pixel (12.0), 0.11 sec (0.03) and 41.6 pixel (18.1), 0.11 sec (0.04), respectively. 1 week postOP, these values were significantly lower (p=0.02; p=0.01) in the CTR eyes than in the eyes with no CTR: Mean (SD) wobble amplitude and wobble time with and without CTR were 34.3 pixel (12.2), 0.09 sec (0.03) and 55.6 pixel (22.1), 0.13 sec (0.05), respectively. 1 hour and 1 week post OP, amplitude and wobble time were similar in PXF eyes compared to non PXF eyes. Mean IOL tilt and decentration were generally low and did not differ between eyes with and without CTR at any time point (p>0.05).
This novel device has been shown to be clinically feasible and to measure wobble effect during eye movements in all eyes examined in this study. Whereas static parameters of IOL in-the-bag stability did not differ between eyes with and without CTR, a significant lower wobble effect was detected in eyes with CTR compared to eyes without implantation of a CTR 1 week postOP. This may be an evidence for a positive effect of a CTR on capsular stability in the early preoperative phase. However, analysis of the complete dataset needs to be awaited, as well as results of 3 months follow-ups, when capsular shrinkage should already be completed.