title: Contrast sensitivity and spherical aberration in eyes implanted with AcrySof IQ and AcrySof Natural intraocular lens: the results of a meta-analysis.
abstract: BACKGROUND
  To systematically evaluate the visual performance of aspheric AcrySof IQ and spherical AcrySof Natural intraocular lens (IOL) after cataract surgery.
  
  
  RESULTS
  Potential randomized controlled trials (RCTs) that involved implanting AcrySof IQ and AcrySof Natural were searched from PubMed, Web of science, EMBASE, Chinese Science and Technology Periodicals Databases and Cochrane Central Register of Controlled Trials. The methodological quality of the studies was assessed by the Jadad method. Standardized mean differences (SMDs) with 95% confidence intervals (CIs) of best-corrected visual acuity (BCVA), contrast sensitivity and spherical aberration were pooled using a random-effects model. Seven studies were identified and analyzed to compare AcrySof IQ (236 eyes) with AcrySof Natural (232 eyes) after phacoemulsification. There was no significant difference in postoperative BCVA between AcrySof IQ and AcrySof Natural (p =0.137) after a follow up of 3 months. For contrast sensitivity, these differences reached statistical significance under photopic conditions at two spatial frequencies (3 cycles per degree (cpd), 6 cpd, 12 cpd, and 18 cpd; p =0.022, p =0.017, p = 0.065, and p=0.191, respectively) and under mesopic conditions at three spatial frequencies (3 cpd, 6 cpd, 12 cpd, and 18 cpd; p =0.007, p =0.033, p =0.030, and p =0.080, respectively). Eyes with AcrySof IQ also had statistically significant less spherical aberration than eyes with AcrySof Natural (p<0.001). Sensitivity analysis showed that the results were relatively stable and reliable.
  
  
  CONCLUSIONS
  The overall findings indicate that AcrySof IQ with a modified aspheric surface induced significantly less spherical aberration than AcrySof Natural. Contrast sensitivity in eyes with AcrySof IQ is better than that in eyes with AcrySof Natural, especially under mesopic conditions.
authors.affiliation: Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Shenyang, People's Republic of China ; Eye Hospital of China Medical University, Shenyang, People's Republic of China ; Key Lens Research Laboratory of Liaoning Province, Shenyang, People's Republic of China.
authors.forename: Jianping
authors.initials: J
authors.lastname: Liu
authors.forename: Jiangyue
authors.initials: J
authors.lastname: Zhao
authors.forename: Liwei
authors.initials: L
authors.lastname: Ma
authors.forename: Guangcong
authors.initials: G
authors.lastname: Liu
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.forename: Jinsong
authors.initials: J
authors.lastname: Zhang
mesh_terms: D002386:Cataract / Q000150:complications / Q000628:therapy; D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D019591:Pseudophakia / Q000209:etiology / Q000503:physiopathology*; D016032:Randomized Controlled Trials as Topic; D014792:Visual Acuity