title: Evaluation of optical coherence tomography retinal thickness parameters for use in clinical trials for neovascular age-related macular degeneration.
abstract: OBJECTIVE
  To investigate the relationship between automated and manually derived measurements of central retinal thickness from optical coherence tomography (OCT) and to determine the relationship between the foveal center point (FCP) and the foveal central subfield (FCS) in neovascular age-related macular degeneration (AMD).
  
  
  METHODS
  Data were collected from 216 patients with newly diagnosed neovascular AMD, who underwent StratusOCT imaging at diagnosis. Raw StratusOCT images for each patient were analyzed with the publicly available custom software OCTOR, which allows accurate manual grading of OCT B-scans. Manually derived central retinal thickness measurements were compared with measurements obtained from automated StratusOCT analysis. Manually obtained measurements of FCP and FCS were also compared.
  
  
  RESULTS
  The mean (+/-SD) difference in thickness between automated and manually derived FCP thickness was 7.9 microm (+/-90.8), but the maximum difference was 455 microm. The limits of agreement (95% confidence interval), between automated and manually obtained FCP thicknesses, were -173.7 microm (lower limit) and 189.6 microm (upper limit), with a coefficient of determination (R(2)) of 0.49 (P < 0.001). In contrast, the R(2) for manually derived FCP and manually derived FCS thickness was 0.94 (P < 0.001), with a smaller mean (+/-SD) difference in thickness of 13.8 microm (+/-29.8).
  
  
  CONCLUSIONS
  Manual correction of errors in automated OCT segmentation may be necessary for accurate interpretation of anatomic outcomes for clinical trials of neovascular AMD. In addition, although measurement of FCS remains preferable for assessment of central retinal thickness, accurate measurement of FCP may represent an adequate alternative when FCS is unavailable.
authors.affiliation: Doheny Image Reading Center, Doheny Eye Institute, Keck School of Medicine of the University of Southern California, Los Angeles, California 90033, USA.
authors.forename: Pearse A
authors.initials: PA
authors.lastname: Keane
authors.forename: Sandra
authors.initials: S
authors.lastname: Liakopoulos
authors.forename: Renu V
authors.initials: RV
authors.lastname: Jivrajka
authors.forename: Karen T
authors.initials: KT
authors.lastname: Chang
authors.forename: Tarek
authors.initials: T
authors.lastname: Alasil
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Walsh
authors.forename: Srinivas R
authors.initials: SR
authors.lastname: Sadda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D020256:Choroidal Neovascularization / Q000145:classification* / Q000175:diagnosis; D002986:Clinical Trials as Topic / Q000592:standards; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008268:Macular Degeneration / Q000145:classification* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D012160:Retina / Q000473:pathology*; D012189:Retrospective Studies; D012984:Software; D041623:Tomography, Optical Coherence / Q000379:methods*; D014792:Visual Acuity