Multifocal IOLs susceptible to decentration in myopic eyes

This prospective study examined the tilt and decentration of multifocal IOLs following implantation in myopic eyes.

Study design

The authors studied 28 myopic (axial length >24.5 D) and 56 emmetropic eyes that underwent phacoemulsification and Tecnis ZMB00 multifocal IOL (Abbott) implantation.

Outcomes included tilt and decentration of the IOLs, high-order aberrations and modulation transfer function (MTF), measured using an OPD-Scan III aberrometer. Subjective symptoms were assessed using a questionnaire.

Outcomes

At 1 year postop, UDVA, CDVA and UNVA did not differ between groups, nor did horizontal decentration or IOL tilt. Vertical decentration, however, was statistically worse in the myopic group. The myopic group also had worse aberration data, poorer MTF and more subjective symptoms than controls.

Axial length negatively correlated with vertical decentration.

Limitations

The study only used the ZMBOO IOL, which is high add and sensitive to centration. Newer lenses, such as the extended-depth of focus IOLs and low add, may not have this issue. One confounding factor is that higher axial length patients have poorer vision—whether it be from the retina or another sources—and are prone to worse aberration, poorer MTF and subjective symptoms even without a multifocal IOL.

Clinical significance

In general, patients with myopia are satisfied after cataract surgery, especially those with high axial lengths. This study suggests ophthalmologists should counsel patients with high axial lengths about the risk of decentration of the lens and worse aberration data. These patients may be better off with a monofocal IOL that is less sensitive to centration but keeps them slightly myopic. However, further studies looking at newer lenses may help to adjust practice patterns.