title: Evaluation of retinal pigment epithelium-Bruch's membrane complex thickness in dry age-related macular degeneration using optical coherence tomography.
abstract: OBJECTIVE
  To compare retinal pigment epithelium-Bruch's membrane (RPE-BM) complex thickness in patients with early and intermediate dry age-related macular degeneration (AMD) and age-matched controls using spectral domain optical coherence tomography (SD-OCT).
  
  
  METHODS
  In this retrospective, cross-sectional study, 25 patients with dry AMD and 25 controls were recruited. SD-OCT scans were manually segmented by two independent investigators. Thickness values were calculated for the nine Early Treatment Diabetic Retinopathy Study (ETDRS) subfields.
  
  
  RESULTS
  RPE-BM thickness was significantly thicker in the dry AMD group (32.3, 30.6 and 28.4 μm for central, inner and outer subfields, respectively) compared with the normal eyes (22.7, 21.8 and 21.6 μm, respectively). RPE-BM thickness was positively correlated with age in the normal group but not in the AMD group. RPE-BM thickness in the dry AMD group was negatively correlated with visual acuity in the central and inner subfields but not in the outer. We observed good intraobserver and inter-observer reliability for both groups in all ETDRS subfields.
  
  
  CONCLUSIONS
  This study reports novel data concerning RPE-BM segmentation in dry AMD and performs a direct comparison with age-matched normal controls. Our findings confirm the electron and light microscopy derived data and also establish the value of OCT in the quantification of the RPE-BM complex.
authors.affiliation: NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, , London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Karampelas
authors.forename: Dawn A
authors.initials: DA
authors.lastname: Sim
authors.forename: Pearse A
authors.initials: PA
authors.lastname: Keane
authors.forename: Vasilios P
authors.initials: VP
authors.lastname: Papastefanou
authors.forename: Srinivas R
authors.initials: SR
authors.lastname: Sadda
authors.forename: Adnan
authors.initials: A
authors.lastname: Tufail
authors.forename: Jonathan
authors.initials: J
authors.lastname: Dowler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016570:Bruch Membrane / Q000473:pathology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008268:Macular Degeneration / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D055213:Retinal Pigment Epithelium / Q000473:pathology*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence / Q000592:standards*; D014792:Visual Acuity
keywords: Imaging; Retina