Study questions benefit of femto-cataract surgery accuracy in capsulorhexis

The supposed advantage of the more predictable capsulorhexis that femtosecond laser surgery can provide may be based on a false assumption about its influence on the security of an IOL's position postoperatively, according to Oliver Findl MD, Vienna, Austria. In a study involving 254 eyes undergoing conventional phacoemulsification which compared the IOL-position in eyes with ideal capsulorhexes to those of eyes with eccentric or small capsulorhexes, there was no statistical significance between the groups regarding the postoperative shift in anterior chamber depth or tilt. Moreover, although the difference in decentration was statistically significant (p=) it was still so small as to be clinically irrelevant, Dr Findl told an international Meeting on Anterior Segment Surgery in Verona, Italy. 'The rhexis effect is weak, and that brings into question whether femtosecond laser will actually result is a better and more predictable IOL positioning,' Dr Findl said. The three groups of patients in the study were similar in terms of preoperative biometry, age and gender and underwent implantation of standard IOLs with a good track record regarding postoperative stability. Measurements with the AC-Master showed that the mean absolute ACD shift between one hour postoperatively and three months postoperatively was 0.24 mm in the optimal capsulorhexis group, 0.25 mm in the eccentric capsulorhexis group and 0.25 mm in the small capsulorhexis group (p=0.352). Similarly, the amount of tilt at three months follow-up was 3.90 degrees in the optimal group, 3.76 degrees in the eccentric group and 3.84 degrees in the small group. And although there was a statistically greater decentration in the eccentric group (p=0.011) the difference was only 0.08 mm.