title: Properties of pattern standard deviation in open-angle glaucoma patients with hemi-optic neuropathy and bi-optic neuropathy.
abstract: OBJECTIVE
  To evaluate the properties of pattern standard deviation (PSD) according to localization of the glaucomatous optic neuropathy.
  
  
  METHODS
  We enrolled 242 eyes of 242 patients with primary open-angle glaucoma, with a best-corrected visual acuity ≥ 20/25, and no media opacity. Patients were examined via dilated fundus photography, spectral-domain optical coherence tomography, and Humphrey visual field examination, and divided into those with hemi-optic neuropathy (superior or inferior) and bi-optic neuropathy (both superior and inferior). We assessed the relationship between mean deviation (MD) and PSD. Using broken stick regression analysis, the tipping point was identified, i.e., the point at which MD became significantly associated with a paradoxical reversal of PSD.
  
  
  RESULTS
  In 91 patients with hemi-optic neuropathy, PSD showed a strong correlation with MD (r = -0.973, β = -0.965, p < 0.001). The difference between MD and PSD ("-MD-PSD") was constant (mean, -0.32 dB; 95% confidence interval, -2.48~1.84 dB) regardless of visual field defect severity. However, in 151 patients with bi-optic neuropathy, a negative correlation was evident between "-MD-PSD" and MD (r2 = 0.907, p < 0.001). Overall, the MD tipping point was -14.0 dB, which was close to approximately 50% damage of the entire visual field (p < 0.001).
  
  
  CONCLUSIONS
  Although a false decrease of PSD usually begins at approximately 50% visual field damage, in patients with hemi-optic neuropathy, the PSD shows no paradoxical decrease and shows a linear correlation with MD.
authors.affiliation: Department of Ophthalmology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Heo
authors.affiliation: Department of Ophthalmology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Kyoung Nam
authors.initials: KN
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Min Woo
authors.initials: MW
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Sung Bok
authors.initials: SB
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Chungnam National University Hospital, Chungnam National University School of Medicine, Daejeon, Korea.
authors.forename: Chang-Sik
authors.initials: CS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D005902:Glaucoma, Open-Angle / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D009901:Optic Nerve Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence