title: Optical coherence tomography assessed retinal nerve fiber layer thickness in patients with Alzheimer's disease: a meta-analysis.
abstract: OBJECTIVE
  To investigate the difference of retinal nerve fiber layer (RNFL) thickness between Alzheimer's disease patients and normal people, so as to provide clue for the early diagnosis of Alzheimer's disease.
  
  
  METHODS
  The articles on the association of RNFL thickness and Alzheimer's disease were retrieved by searching international and national databases. The qualified articles were assessed by meta analysis with Stata11.0 software. The results were pooled using weighted mean difference (WMD) with a corresponding 95% confidence interval (CI).
  
  
  RESULTS
  Totally 7 studies enrolled 324 eyes were included in the meta-analysis. The results of meta analysis showed that in AD patients, there was a significant average RNFL thickness reduction compared with the control group [WMD=-17.561, 95%CI: (-23.971, -11.151)]. There were significant differences in superior, inferior, nasal and temporal RNFL thickness between the two groups. WMD with a 95%CI were [-18.829, 95%CI:(-25.915, -11.743); P<0.05], [-25.775, 95%CI:(-34.304, -17.247); P<0.05], [-16.877, 95%CI: (-29.141, -4.613); P<0.001] and [-14.565, 95%CI:(-28.002, -1.128); P<0.001] respectively. Begg's test and Egger's test did not show significant difference, funnel plot was basically symmetrical, indicating that there was no publication bias existed.
  
  
  CONCLUSIONS
  There are significant differences in the RNFL thickness in all quadrants between the two groups. RNFL thickness is reduced in AD patients compared with the control group.
authors: Key Laboratory of Lens Research Liaoning Province, Department of Ophthalmology, Eye Hospital of China Medical University, the Fourth Affiliated Hospital of China Medical University Shenyang 110005, Liaoning Province, China.
authors: Xue-Fei
authors: XF
authors: He
authors: Yi-Ting
authors: YT
authors: Liu
authors: Cheng
authors: C
authors: Peng
authors: Fan
authors: F
authors: Zhang
authors: Shi
authors: S
authors: Zhuang
authors: Jin-Song
authors: JS
authors: Zhang