A prospective, randomized, double-masked comparison of a zonal-progressive multifocal intraocular lens and a monofocal intraocular lens.
INTRODUCTION: Multifocal intraocular lenses (IOLs) have been designed to provide improved near visual acuity without spectacles compared with monofocal IOLs. Early studies have reported variables amounts of decreased visual acuity and contrast sensitivity with multifocal IOLs, and some patients have experienced halos and glare. METHODS: The authors performed a prospective, double-masked, multicenter evaluation of 62 patients randomized between a new zonal-progressive optic multifocal IOL and a monofocal IOL. RESULTS: Mean postoperative spherical equivalent, astigmatism, and uncorrected and best-corrected distance visual acuity were similar between the two groups. Patients with a multifocal IOL achieved significantly better uncorrected near visual acuity than patients with monofocal IOLs (J3+ versus J7; P less than 0.0001). With distance correction only, mean near visual acuity was J2 versus J5- (P = 0.0001). Best-corrected near visual acuity was J1 for both groups, with 1.36 diopters (D) for the multifocal group versus 2.37 D for the monofocal group (P less than 0.0001). Regan contrast sensitivity was lower for the multifocal patients at all contrast levels, and achieved statistical significance at very low contrast (11% contrast; P = 0.0024). Fifty-two percent of patients with a multifocal IOL reported that they did not need spectacles at all or used them only for their fellow eye, compared with 25% of the patients with monofocal IOLs. CONCLUSION: Both monofocal and multifocal implant patients were very satisfied with the results of their cataract extraction and IOL implant surgery. A small loss of contrast sensitivity with the multifocal IOL was demonstrated, consistent with theoretical predictions. The functional significance of the loss of contrast sensitivity appears to be small and counterbalanced by the advantage of improved uncorrected near visual acuity.