A systematic review and meta-analysis of retinal nerve fiber layer change in dementia, using optical coherence tomography

IntroductionRetinal nerve fiber layer (RNFL) thinning, assessed by optical coherence tomography (OCT), has recently been reported in various dementias.MethodsWe conducted a systematic review and meta-analysis to investigate the diagnostic utility of RNFL thickness measurement using OCT in dementia (including Alzheimer's disease [AD] and mild cognitive impairment [MCI]) compared with healthy controls (HC).ResultsSeventeen studies comparing AD with HC (702 AD eyes and 790 HC eyes) were included, demonstrating a significant reduction in mean RNFL thickness in AD (weighted mean difference [WMD] 12.44, 95% confidence interval or CI [−16.64, −8.25], P <.0001). Five studies comparing MCI and HC (214 MCI eyes and 421 HC eyes) were included demonstrating a significant reduction in mean RNFL thickness in MCI (WMD −8.23, 95% CI [−14.00, −2.45], P =.005). No relevant studies were identified for other dementias.DiscussionOCT measurement of RNFL thickness appears diagnostically useful in discriminating between AD, or MCI, and HC.