Visual outcome comparison of unilateral versus bilateral implantation of apodized diffractive multifocal intraocular lenses after cataract extraction: prospective 6-month study

To evaluate the visual outcomes and patient satisfaction after unilateral implantation or stepwise bilateral implantation of an apodized diftractive multifocal intraocular lens (IOL).

Private practice, Cincinnati, Ohio, USA.

Patients requiring cataract surgery in 1 eye were recruited. AcrySof ReSTOR IOLs were implanted in 1 eye of patients with phakic contralateral eyes, patients with contralateral monofocal IOLs, and patients with a contralateral multifocal IOL of the same model. Six months postoperatively, patients were assessed for visual acuity (31.0 cm, 50.0 cm, 4.0 m), contrast sensitivity, and stereopsis. Patients were surveyed for visual disturbances and lifestyle visual quality.

Of unilateral multifocal IOL patients, 75% were satisfied with their vision (score 7.3 out of 10) and a majority (56% multifocal-phakic, 65% multifocal-monofocal) achieved spectacle independence. These values were slightly lower than values for bilateral multifocal patients (92% satisfied, 77% spectacle independent), but not at a statistically significant level. Mean overall patient satisfaction was statistically significantly different: 8.9 for bilateral patients versus 7.3 for unilateral patients. Objectively, significant differences favored bilateral implantation over unilateral implantation for stereopsis, uncorrected near visual acuity, and best corrected near and intermediate visual acuities. Contrast sensitivity was similar between groups in most cases. The incidence of halos was lower in unilateral patients (57%) than in bilateral patients (77%), although the difference did not reach statistical significance.

Although unilateral implantation of a multifocal IOL provided patients with high levels of spectacle freedom and good visual acuity without compromising contrast sensitivity, overall clinical results favored bilateral implantation.