title: Differential vulnerability of retinal layers to early age-related macular degeneration: evidence by SD-OCT segmentation analysis.
abstract: OBJECTIVE
  We evaluated layer-by-layer retinal thickness in spectral-domain optical coherence tomography (SD-OCT), determined by automated segmentation analysis (ASA) software in healthy and early age-related maculopathy (ARM) eyes.
  
  
  METHODS
  There were 57 eyes (specifically, 19 healthy eyes under 60 years old, 19 healthy eyes over 60, and 19 ARM eyes) recruited into this cross-sectional study. The mean ages were 36.78 (SD, ±13.82), 69.89 (SD, ±6.14), and 66.10 (SD, ±8.67) years, respectively, in the three study groups. The SD-OCT scans were transferred into a dedicated software program that performed automated segmentation of different retinal layers.
  
  
  RESULTS
  Automated layer segmentation showed clear boundaries between the following layers: retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GCL+IPL), inner nuclear layer plus outer plexiform layer (INL+OPL), outer nuclear layer (ONL), and RPE complex. The thickness of the RNFL, ONL, and RPE layers did not show a statistically significant change across the three groups by ANOVA (P = 0.10, P = 0.09, P = 0.15, respectively). The thickness of GCL+IPL and INL+OPL was significantly different across the groups (P < 0.01), being reduced in the ARM eyes compared to healthy eyes, under and over 60 years old.
  
  
  CONCLUSIONS
  The early morphologic involvement of the GCL+IPL and INL+OPL layers in ARM eyes, as revealed by the ASA, could be related to early anatomic changes described in the inner retina of ARM eyes. This finding may represent a morphologic correlation to the deficits in postreceptoral retinal function in ARM eyes.
authors.affiliation: Institute of Ophthalmology, Catholic University "Sacro Cuore," Rome, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Savastano
authors.forename: Angelo Maria
authors.initials: AM
authors.lastname: Minnella
authors.forename: Antonello
authors.initials: A
authors.lastname: Tamburrino
authors.forename: Gaspare
authors.initials: G
authors.lastname: Giovinco
authors.forename: Salvatore
authors.initials: S
authors.lastname: Ventre
authors.forename: Benedetto
authors.initials: B
authors.lastname: Falsini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008268:Macular Degeneration / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012165:Retinal Ganglion Cells / Q000473:pathology*; D013997:Time Factors; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity; D055815:Young Adult
keywords: age-related maculopathy; automated segmentation analysis; ischemia; postreceptoral retina; spectral domain optical coherence tomography