title: Transretinal degeneration in ageing human retina: a multiphoton microscopy analysis.
abstract: OBJECTIVE
  Retinal cell remodelling has been reported as a consistent feature of ageing. However, the degree to which this results in transretinal degeneration is unclear. To address this, the authors used multiphoton microscopy to quantify retinal degeneration in post-mortem human eyes of two age groups.
  
  
  METHODS
  Retinas from six young subjects (18-33 years old) and six older subjects (74-90 years old) were prepared as wholemount preparations. All retinas were stained with 4,6-diamidino-2-phenylindole and imaged by multiphoton confocal microscopy to quantify neuron densities in the retinal ganglion cell layer (RGCL), inner nuclear layer (INL) and outer nuclear layer (ONL). Neurons were counted using automated cell identification algorithms. All retinas were imaged hydrated to minimise tissue artefacts.
  
  
  RESULTS
  In both groups, 56% of the area within the central 4 mm eccentricity and 27% of the area with eccentricity between 4 mm and 7 mm were imaged. Compared with young subjects, the peak RGCL neuron loss in the aged subjects (25.5%) was at 1 mm eccentricity. INL and ONL neuron densities significantly decreased at 1-2 mm eccentricity (8.7%) and 0.5-4 mm eccentricity (15.6%) respectively (P <0.05). The reduction in neuron density in the INL corresponded, spatially, to the region with the greatest neuron loss in the RGCL and ONL.
  
  
  CONCLUSIONS
  This is the first study to correlate neurodegeneration in different populations of cells in the ageing retinas. These data confirm that the greatest neuronal loss occurs in the RGCL and ONL in human ageing retinas, whereas the INL is relatively preserved.
authors.affiliation: Optometry and Vision Sciences, Cardiff University, Cardiff, UK.
authors.forename: Y
authors.initials: Y
authors.lastname: Lei
authors.forename: N
authors.initials: N
authors.lastname: Garrahan
authors.forename: B
authors.initials: B
authors.lastname: Hermann
authors.forename: M P
authors.initials: MP
authors.lastname: Fautsch
authors.forename: D H
authors.initials: DH
authors.lastname: Johnson
authors.forename: M R
authors.initials: MR
authors.lastname: Hernandez
authors.forename: M
authors.initials: M
authors.lastname: Boulton
authors.forename: J E
authors.initials: JE
authors.lastname: Morgan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002452:Cell Count; D016922:Cellular Senescence / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods; D009410:Nerve Degeneration / Q000473:pathology* / Q000503:physiopathology; D012165:Retinal Ganglion Cells / Q000473:pathology* / Q000502:physiology; D055815:Young Adult