title: Visual function and higher order aberration after implantation of aspheric and spherical multifocal intraocular lenses: a meta-analysis.
abstract: OBJECTIVE
  To assess the visual outcomes of aspheric multifocal intraocular lenses (IOLs) compared with spherical multifocal IOL after cataract surgery.
  
  
  METHODS
  Potential prospective controlled trials that comparing aspheric multifocal IOL implantation with spherical multifocal IOL group were extracted from the computer database. The statistical analysis was carried out using Stata 10 software. Standardized mean differences with 95% confidence intervals (CIs) were calculated for continuous variables. The pooled estimates were computed in the use of a random-effects model.
  
  
  RESULTS
  A systematic review identified five prospective nonrandomized controlled trials, including 178 aspheric multifocal IOL and 164 spherical multifocal IOL. There was no significant difference in uncorrected distance visual acuity (95%CI, -0.248 to 0.152;P=0.641) and uncorrected near visual acuity (95%CI, -0.210 to 0.428;P=0.504) between aspheric multifocal IOL and spherical multifocal IOL. Statistically significant differences were detected less spherical aberration in aspheric multifocal IOL (95%CI, -1.111 to -0.472; P<0.001) when compared to spherical multifocal IOL. Spherical multifocal IOL showed a greater higher order aberration compared to the aspheric multifocal IOL (95%CI, -1.024 to-0.293; P<0.001). Sensitivity analysis suggested that the results were relatively reliable.
  
  
  CONCLUSIONS
  The overall findings indicated that aspheric multifocal IOL and spherical multifocal IOL provided similar visual acuity at near and distance. Patients implanted with aspheric multifocal IOL had less spherical aberration and higher order aberration than patients with spherical multifocal IOL. Further well-organized, prospective controlled trials involving larger patient numbers are needed.
authors.affiliation: Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University, Key Lens Research Laboratory of Liaoning Province, Shenyang 110005, Liaoning Province, China.
authors.forename: Jian-Ping
authors.initials: JP
authors.lastname: Liu
authors.forename: Fan
authors.initials: F
authors.lastname: Zhang
authors.forename: Jiang-Yue
authors.initials: JY
authors.lastname: Zhao
authors.forename: Li-Wei
authors.initials: LW
authors.lastname: Ma
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Zhang
keywords: aspheric multifocal intraocular lens; higher order aberration; meta-analysis; spherical multifocal intraocular lens; uncorrected distance visual acuity; uncorrected near visual acuity