Stereoacuity and aniseikonia after unilateral and bilateral implantation of the Array refractive multifocal intraocular lens.

PURPOSE

To evaluate stereoacuity and aniseikonia in eyes with unilateral and bilateral implantation of the Allergan Array refractive multifocal intraocular lens (MIOL).

SETTING

Department of Ophthalmology, University Hospital, Kiel, Germany.

METHODS

This study comprised 31 patients with a unilateral MIOL and a phakic fellow eye and 29 patients with bilateral MIOLs. In all pseudophakic eyes, an Array MIOL had been implanted between 1991 and 1994 during a prospective clinical trial. In the present study, patients were re-examined. Near and distance visual acuity were tested; binocular functions were assessed using Bagolini lenses, the Worth 4-dot test, the Lang random-dot test, and the Titmus fly chart. Aniseikonia was evaluated using Aulhorn's phase-difference haploscope. Mean follow-up was 43 months in both groups.

RESULTS

After unilateral implantation 87.1% of patients and after bilateral implantation 93.1% of patients correctly perceived the stereograms of the Lang random-dot test. The mean subjective height of the measured Titmus fly was 4.2 cm after unilateral and 4.3 cm after bilateral implantation. The stereoacuity tests revealed no statistically significant differences between the groups. Distance and near aniseikonia were significantly less after bilateral than after unilateral implantation.

CONCLUSION

Despite the simultaneous formation of multiple retinal images, the Array MIOL allowed good binocular vision including random-dot stereopsis. Functional aniseikonia developed but did not interfere with normal binocular vision.