title: The impact on vision of aspheric to spherical monofocal intraocular lenses in cataract surgery: a systematic review with meta-analysis.
abstract: OBJECTIVE
  To provide a summary of the impact on vision of an aspheric intraocular lens (IOL) compared with a spherical IOL in cataract surgery.
  
  
  METHODS
  Systematic review with meta-analysis.
  
  
  METHODS
  Patients from published randomized controlled trials (RCTs) of cataract surgery with aspheric compared with spherical monofocal IOL implantation.
  
  
  METHODS
  We systematically searched the peer-reviewed literature in MEDLINE, EMBASE, Web of Science, BIOSIS, and the Cochrane Library according to the Cochrane Collaboration method to identify relevant RCTs. The inclusion criteria were RCTs on cataract surgery comparing the use of aspheric versus spherical IOL implantation that assessed visual acuity, contrast sensitivity, or quality of vision. The effects were calculated as mean differences or standardized mean differences (Hedges' g) and pooled using random-effect models.
  
  
  METHODS
  Best-corrected visual acuity (BCVA), contrast sensitivity, and subjective perception of the quality of vision.
  
  
  RESULTS
  Forty-three studies provided data and were included, comprising 2076 eyes implanted with aspheric IOLs and 2034 eyes implanted with spherical IOLs. The BCVA showed a significant difference for aspheric IOLs (-0.01 logarithm of the minimum angle of resolution; 95% confidence interval [CI], -0.02 to -0.00). For contrast sensitivity, a significant advantage for aspheric IOLs was found under photopic and mesopic light conditions (photopic: Hedges' g 0.42, 95% CI 0.24-0.61 (3 cycles per degree [cpd]) to 0.53, 95% CI 0.33-0.73 (12 cpd); mesopic: Hedges' g 0.49, 95% CI 0.23-0.75 (1.5 cpd) to 0.76, 95% CI 0.52-1.00 (18 cpd)). Questionnaires targeting the subjective perception of quality of vision yielded less conclusive results.
  
  
  CONCLUSIONS
  Overall, a patient may achieve better contrast sensitivity with an aspheric IOL than with a spherical IOL, especially under dim light. There was no clinically relevant difference in BCVA between aspheric and spherical IOL implantation. The findings on the subjective perception of visual quality were heterogeneous with no clear result favoring either option.
authors.affiliation: Mannheim Institute for Public Health, Social and Preventive Medicine, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany; Medical Physics, Mannheim Medical School, University of Heidelberg, Heidelberg, Germany. Electronic address: alexander.k.schuster@gmx.de.
authors.forename: Alexander K
authors.initials: AK
authors.lastname: Schuster
authors.forename: Jonas
authors.initials: J
authors.lastname: Tesarz
authors.forename: Urs
authors.initials: U
authors.lastname: Vossmerbaeumer
mesh_terms: D002387:Cataract Extraction; D015350:Contrast Sensitivity / Q000502:physiology*; D016208:Databases, Factual; D006801:Humans; D019654:Lens Implantation, Intraocular; D007910:Lenses, Intraocular; D019591:Pseudophakia / Q000503:physiopathology*; D011788:Quality of Life; D016032:Randomized Controlled Trials as Topic; D014792:Visual Acuity / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*