title: [Retinal imaging of the macula and optic disc in neurodegenerative diseases].
abstract: BACKGROUND
  Due to current demographic trends, the prevalence of mild cognitive impairment and dementia is expected to increase considerably. For potential new therapies it is important to identify patients at risk as early as possible. Currently, there is no population-based screening. Therefore, identification of biomarkers that will help screen the population at risk is urgently needed. Thus, a literature review on retinal pathology in neurodegenerative diseases was performed.
  
  
  METHODS
  PubMed was searched for studies published up to August 2016 using the following keywords: "mild cognitive impairment", "dementia", "eye", "ocular biomarkers", "OCT" and "OCT angiography". Relevant publications were selected and summarized qualitatively.
  
  
  RESULTS
  Multiple studies using noninvasive in vivo optical coherence tomography (OCT) imaging showed nonspecific retinal pathological changes in patients with neurodegenerative diseases such as mild cognitive impairment, Alzheimer's and Parkinson's disease. Pathological changes in macular volume, optic nerve fiber layer thickness and the ganglion cell complex were observed. However, based on available evidence, no ocular biomarkers for neurodegeneration which could be integrated in routine clinical diagnostics have been identified.
  
  
  CONCLUSIONS
  The potential use of OCT in the early diagnostic workup and monitoring of progression of neurodegenerative diseases needs to be further explored in longitudinal studies with large cohorts.
authors.affiliation: Universitäts-Augenklinik Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Deutschland.
authors.forename: G N
authors.initials: GN
authors.lastname: Turski
authors.affiliation: Universitäts-Augenklinik Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Deutschland.
authors.forename: S
authors.initials: S
authors.lastname: Schmitz-Valckenberg
authors.affiliation: Universitäts-Augenklinik Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Deutschland.
authors.forename: F G
authors.initials: FG
authors.lastname: Holz
authors.affiliation: Universitäts-Augenklinik Bonn, Ernst-Abbe-Str. 2, 53127, Bonn, Deutschland. robert.finger@ukb.uni-bonn.de.
authors.forename: R P
authors.initials: RP
authors.lastname: Finger
mesh_terms: D000375:Aging / Q000473:pathology*; D019317:Evidence-Based Medicine; D006801:Humans; D008266:Macula Lutea / Q000000981:diagnostic imaging / Q000473:pathology*; D019636:Neurodegenerative Diseases / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology*; D009898:Optic Disk / Q000000981:diagnostic imaging / Q000473:pathology*; D011379:Prognosis; D015203:Reproducibility of Results; D042262:Retinoscopy / Q000379:methods / Q000706:statistics & numerical data; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods* / Q000706:statistics & numerical data*
keywords: Dementia; Ganglion cells; Optical coherence tomography; Retina; Screening