title: Lower cognitive function in patients with age-related macular degeneration: a meta-analysis.
abstract: OBJECTIVE
  To investigate the cognitive impairment in patients with age-related macular degeneration (AMD).
  
  
  METHODS
  Relevant articles were identified through a search of the following electronic databases through October 2015, without language restriction: 1) PubMed; 2) the Cochrane Library; 3) EMBASE; 4) ScienceDirect. Meta-analysis was conducted using STATA 12.0 software. Standardized mean differences with corresponding 95% confidence intervals were calculated. All of the included studies met the following four criteria: 1) the study design was a case-control or randomized controlled trial (RCT) study; 2) the study investigated cognitive function in the patient with AMD; 3) the diagnoses of AMD must be provided; 4) there were sufficient scores data to extract for evaluating cognitive function between cases and controls. The Newcastle-Ottawa Scale criteria were used to assess the methodological quality of the studies.
  
  
  RESULTS
  Of the initial 278 literatures, only six case-control and one RCT studies met all of the inclusion criteria. A total of 794 AMD patients and 1,227 controls were included in this study. Five studies were performed with mini-mental state examination (MMSE), two studies with animal fluency, two studies with trail making test (TMT)-A and -B, one study with Mini-Cog. Results of the meta-analysis revealed lower cognitive function test scores in patients with AMD, especially with MMSE and Mini-Cog test (P≤0.001 for all). The results also showed that differences in the TMT-A (except AMD [total] vs controls) and TMT-B test had no statistical significance (P>0.01). The Newcastle-Ottawa Scale score was ≥5 for all of the included studies. Based on the sensitivity analysis, no single study influenced the overall pooled estimates.
  
  
  CONCLUSIONS
  This meta-analysis suggests lower cognitive function test scores in patients with AMD, especially with MMSE and Mini-Cog test. The other cognitive impairment screening tests, such as animal fluency test and TMT, need more studies to assess.
authors.affiliation: Department of Ophthalmology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
authors.forename: Li-Xiao
authors.initials: LX
authors.lastname: Zhou
authors.affiliation: Department of Ophthalmology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
authors.forename: Cheng-Lin
authors.initials: CL
authors.lastname: Sun
authors.affiliation: Department of Ophthalmology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Wei
authors.affiliation: Department of Ophthalmology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
authors.forename: Zhi-Min
authors.initials: ZM
authors.lastname: Gu
authors.affiliation: Department of Ophthalmology, The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Lv
authors.affiliation: Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, People's Republic of China.
authors.forename: Yalong
authors.initials: Y
authors.lastname: Dang
mesh_terms: D000367:Age Factors; D003071:Cognition; D003072:Cognition Disorders / Q000175:diagnosis*; D006801:Humans; D008268:Macular Degeneration / Q000523:psychology*; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D016032:Randomized Controlled Trials as Topic
keywords: age-related macular degeneration; cognitive impairment; meta-analysis; mini mental state examination