title: A novel method to detect local ganglion cell loss in early glaucoma using spectral-domain optical coherence tomography.
abstract: OBJECTIVE
  To test the glaucoma-discriminating ability of a new method for detecting local ganglion cell loss using spectral-domain optical coherence tomography (OCT).
  
  
  METHODS
  This study included 58 glaucomatous and 48 healthy eyes from Japanese subjects. Combined thickness of the ganglion cell layer and inner plexus layer (GCIPL) was measured on a macular cube scan in Cirrus HD-OCT. Average GCIPL thickness within a macular elliptical annulus and minimum GCIPL thickness on 360 spokes extending from the inner to the outer radius of the elliptical annulus were calculated. Area under the receiver operating characteristic curve (AROC) to discriminate between healthy eyes and early (mean deviation [MD], ≥-6 dB)/advanced (MD, <-6 dB) glaucomatous were compared between parameters.
  
  
  RESULTS
  Forty-three were normal-tension glaucoma, and 15 were high-tension glaucoma. The mean minimum GCIPL thickness was 77.0 μm in healthy eyes and 60.6 μm in glaucomatous eyes (P < 0.001). For the intersession repeatability, the coefficients of variation for average GCIPL and minimum GCIPL were 0.98 and 1.85 in glaucomatous eyes, and 0.89 and 1.85 in healthy eyes, respectively. Minimum GCIPL thickness AROC (0.896) was significantly higher (P = 0.0062) than average GCIPL thickness (0.821) for early glaucoma, whereas minimum GCIPL AROC (0.991) was comparable (P = 0.103) to average GCIPL (0.964) for advanced glaucoma. The minimum GCIPL thickness AROC was comparable (P = 0.861) to average circumpapillary retinal nerve fiber layer (cpRNFL) thickness (0.890) for early glaucoma.
  
  
  CONCLUSIONS
  In Japanese patients with 74.1% of normal-tension glaucoma, the minimum GCIPL on spokes may be useful for detecting early glaucoma.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Kohei
authors.initials: K
authors.lastname: Takayama
authors.forename: Masanori
authors.initials: M
authors.lastname: Hangai
authors.forename: Mary
authors.initials: M
authors.lastname: Durbin
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakano
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morooka
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Akagi
authors.forename: Hanako Ohashi
authors.initials: HO
authors.lastname: Ikeda
authors.forename: Nagahisa
authors.initials: N
authors.lastname: Yoshimura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D019540:Area Under Curve; D016923:Cell Death; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D057066:Low Tension Glaucoma / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000175:diagnosis*; D012372:ROC Curve; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012680:Sensitivity and Specificity; D041623:Tomography, Optical Coherence / Q000379:methods*; D014065:Tonometry, Ocular; D058609:Visual Field Tests; D014794:Visual Fields