Decentration and tilt of polymethyl methacrylate, silicone, and acrylic soft intraocular lenses.

PURPOSE

The purpose of the study is to investigate the periodic changes regarding the decentration and tilt of the intraocular lens (IOL) and to compare any differences in the decentration and tilt among polymethyl methacrylate (PMMA), silicone, and acrylic soft IOLs.

METHODS

A total of 225 cataractous eyes undergoing IOL implant surgery were randomized into 3 groups based on the type of IOL: group A, one-piece PMMA IOL; group B, three-piece silicone IOL; and group C, three-piece acrylic soft IOL. Both the length of the decentration and the degree of the tilt of the IOL were quantitated using the Anterior Eye Segment Analysis System (EAS-1000). All eyes underwent EAS-1000 examinations at 1 week as well as 1, 3, 6, 9, and 12 months after surgery.

RESULTS

All IOLs were confirmed to be implanted accurately in the capsular bag after continuous curvilinear capsulorhexis was accomplished. No statistically significant differences were observed regarding the IOL decentration or tilt between the various postoperative periods in any of the three IOL groups. Furthermore, the differences regarding both the IOL decentration and the tilt between the three IOLs were not determined to be statistically significant throughout the observation period.

CONCLUSIONS

As long as the IOL was placed properly in the capsular bag after the continuous capsulorhexis, neither the decentration nor the tilt of the IOL showed a significant progression up to 12 months after surgery. Furthermore, both the extent of the decentration and tilt almost were the same among the PMMA, silicone, and acrylic soft IOLs.