Objective: To assess the visual effects of multifocal intraocular lenses (IOLs) compared with the current standard treatment of monofocal IOL implantation.
Design: Systematic literature review and meta-analysis of randomized controlled trials.
Methods: The study was performed according to the Cochrane Collaboration methodology. Computer database and manual searches were made to identify all randomized trials comparing multifocal IOL implantation with a monofocal control group. Data were extracted using a standardized form and analyzed using Review Manager software. When study reporting allowed meaningful comparison, meta-analysis was performed. The chi-square test was used to examine heterogeneity between studies. Odds ratios were calculated for dichotomous outcomes and standardized mean differences for continuous variables.
Main outcome measures: There is no single outcome measure that can be thought of as summarizing the efficacy of an IOL. A number of different outcomes had to be examined. The primary outcomes for this review were distance and near visual acuity (unaided and corrected) and spectacle dependence. The secondary outcomes for this review included depth of field, contrast sensitivity, glare, subjective assessment of quality of life or visual function, and surgical complications.
Results: Eight trials were identified. There was significant variability among the trials in the outcomes reported. Distance acuity was similar in multifocal and monofocal IOLs. Unaided near vision tended to improve with the multifocal IOL. This resulted in decreased spectacle dependence with use of the multifocal IOL. Adverse effects included reduced contrast sensitivity and the subjective experience of halos around lights.
Conclusions: Multifocal IOLs are effective at improving near vision relative to monofocal IOLs. Whether that improvement outweighs the adverse effects of multifocal IOLs will vary between patients, with motivation to achieve spectacle independence likely to be the deciding factor.