title: Structural Change Can Be Detected in Advanced-Glaucoma Eyes.
abstract: To compare spectral-domain optical coherence tomography (SD-OCT) standard structural measures and a new three-dimensional (3D) volume optic nerve head (ONH) change detection method for detecting change over time in severely advanced-glaucoma (open-angle glaucoma [OAG]) patients.
  
  
  
  Thirty-five eyes of 35 patients with very advanced glaucoma (defined as a visual field mean deviation < -21 dB) and 46 eyes of 30 healthy subjects to estimate aging changes were included. Circumpapillary retinal fiber layer thickness (cpRNFL), minimum rim width (MRW), and macular retinal ganglion cell-inner plexiform layer (GCIPL) thicknesses were measured using the San Diego Automated Layer Segmentation Algorithm (SALSA). Progression was defined as structural loss faster than 95th percentile of healthy eyes. Three-dimensional volume ONH change was estimated using the Bayesian-kernel detection scheme (BKDS), which does not require extensive retinal layer segmentation.
  
  
  
  The number of progressing glaucoma eyes identified was highest for 3D volume BKDS (13, 37%), followed by GCPIL (11, 31%), cpRNFL (4, 11%), and MRW (2, 6%). In advanced-OAG eyes, only the mean rate of GCIPL change reached statistical significance, -0.18 μm/y (P = 0.02); the mean rates of cpRNFL and MRW change were not statistically different from zero. In healthy eyes, the mean rates of cpRNFL, MRW, and GCIPL change were significantly different from zero. (all P < 0.001).
  
  
  
  Ganglion cell-inner plexiform layer and 3D volume BKDS show promise for identifying change in severely advanced glaucoma. These results suggest that structural change can be detected in very advanced disease. Longer follow-up is needed to determine whether changes identified are false positives or true progression.
authors.affiliation: Shiley Eye Institute Hamilton Glaucoma Center, University of California, San Diego, La Jolla, California, United States.
authors.forename: Akram
authors.initials: A
authors.lastname: Belghith
authors.affiliation: Shiley Eye Institute Hamilton Glaucoma Center, University of California, San Diego, La Jolla, California, United States.
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Medeiros
authors.affiliation: Shiley Eye Institute Hamilton Glaucoma Center, University of California, San Diego, La Jolla, California, United States.
authors.forename: Christopher
authors.initials: C
authors.lastname: Bowd
authors.affiliation: Harkness Eye Institute, Columbia University, New York, New York, United States.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Liebmann
authors.affiliation: Ophthalmology, University of Alabama, Birmingham, Alabama, United States.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Girkin
authors.affiliation: Shiley Eye Institute Hamilton Glaucoma Center, University of California, San Diego, La Jolla, California, United States.
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.affiliation: Shiley Eye Institute Hamilton Glaucoma Center, University of California, San Diego, La Jolla, California, United States.
authors.forename: Linda M
authors.initials: LM
authors.lastname: Zangwill
mesh_terms: D000368:Aged; D000465:Algorithms; D001499:Bayes Theorem; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009898:Optic Disk / Q000473:pathology*; D012372:ROC Curve; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence / Q000379:methods*; D058609:Visual Field Tests; D014794:Visual Fields