title: Human chorioretinal layer thicknesses measured in macula-wide, high-resolution histologic sections.
abstract: OBJECTIVE
  To provide a comprehensive description of chorioretinal layer thicknesses in the normal human macula, including two-layer pairs that can produce a combined signal in some optical coherence tomography (OCT) devices (ganglion cell [GCL] and inner plexiform [IPL] layers and outer plexiform [OPL] and outer nuclear [ONL] layers).
  
  
  METHODS
  In 0.8-μm-thick, macula-wide sections through the foveola of 18 donors (age range, 40-92 years), 21 layers were measured at 25 locations by a trained observer and validated by a second observer. Tissue volume changes were assessed by comparing total retinal thickness in ex vivo OCT and in sections.
  
  
  RESULTS
  Median tissue shrinkage was 14.5% overall and 29% in the fovea. Histologic laminar boundaries resembled those in SD-OCT scans, but the shapes of the foveolar OPL and ONL differed. Histologic GCL, IPL, and OPLHenle were thickest at 0.8. to 1, 1.5, and 0.4 mm eccentricity, respectively. ONL was thickest in an inward bulge at the foveal center. At 1 mm eccentricity, GCL, INL, and OPLHenle represented 17.3% to 21.1%, 18.0% to 18.5%, and 14.2% to 16.6% of total retinal thickness, respectively. In donors ≥ 70 years of age, the RPE and choroid were 17.1% and 29.6% thinner and OPLHenle was 20.8% thicker than in donors <70 years.
  
  
  CONCLUSIONS
  In this study, the first graphic representation and thickness database of chorioretinal layers in normal macula were generated. Newer OCT systems can separate GCL from IPL and OPLHenle from ONL, with good agreement for the proportion of retinal thickness occupied by OPLHenle in OCT and histology. The thickening of OPLHenle in older eyes may reflect Müller cell hypertrophy associated with rod loss.
authors.affiliation: Department of Ophthalmology, University of Alabama at Birmingham, Birmingham, Alabama 35294-0019, USA. curcio@uab.edu
authors.forename: Christine A
authors.initials: CA
authors.lastname: Curcio
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Messinger
authors.forename: Kenneth R
authors.initials: KR
authors.lastname: Sloan
authors.forename: Arnab
authors.initials: A
authors.lastname: Mitra
authors.forename: Gerald
authors.initials: G
authors.lastname: McGwin
authors.forename: Richard F
authors.initials: RF
authors.lastname: Spaide
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002829:Choroid / Q000166:cytology*; D016208:Databases, Factual; D005125:Eye Banks; D005260:Female; D006801:Humans; D008266:Macula Lutea / Q000166:cytology*; D008297:Male; D008867:Microtomy; D008875:Middle Aged; D009445:Neuroanatomy / Q000592:standards; D012016:Reference Values; D012165:Retinal Ganglion Cells / Q000166:cytology*; D041623:Tomography, Optical Coherence / Q000379:methods* / Q000592:standards*