title: Topographic correlation between optic nerve head characteristics and retinal nerve fibre layer defect in primary open-angle glaucoma patients: Korea National Health and Nutrition Examination Survey.
abstract: OBJECTIVE
  To evaluate topographic correlations of the directions of β-zone peripapillary atrophy (PPA) and optic disc torsion with retinal nerve fibre layer (RNFL) defect in a Korean population.
  
  
  METHODS
  Among 292 primary open-angle glaucoma (POAG) patients from the 2012 KNHANES (n = 7444, age ≥ 19 years), 93 eyes of 93 individuals with a single localized RNFL defect were enrolled. The angular locations of the point of maximum radial extent (PMRE) of β-zone PPA and the optic disc torsion were measured on fundus photography. The angular location of the PMRE and the torsion degree (TD) were noted when the absolute value of the former or the latter was ≥15 degrees from the reference line, a line drawn from the centre of the optic disc to the fovea.
  
  
  RESULTS
  The overall POAG prevalence was estimated as 4.2% (95% confidence interval [CI], 3.6-4.9). Of the POAG eyes with a single localized RNFL defect, 39.5% had superior or inferior PMRE of β-zone PPA; in 74.9% (p = 0.015) of those cases, the RNFL defect was located in the same hemifield as the angular location of the PMRE. Meanwhile, 40.4% of the POAG eyes with a single localized RNFL defect showed accompanying optic disc torsion. The correlation rate between the direction of the optic disc torsion and the RNFL defect location was 60.2% (p = 0.029).
  
  
  CONCLUSIONS
  In the Korean POAG patients examined, the directions of the PMRE of β-zone PPA and of the optic disc torsion showed significant associations with the RNFL defect location.
authors.affiliation: Department of Ophthalmology, Keimyung University College of Medicine, Daegu, Korea.
authors.forename: Chong Eun
authors.initials: CE
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.|Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Young Kook
authors.initials: YK
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.|Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Jin Wook
authors.initials: JW
authors.lastname: Jeoung
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.|Department of Ophthalmology, SMG - SNU Boramae Medical Center, Seoul, Korea.
authors.forename: Seok Hwan
authors.initials: SH
authors.lastname: Kim
authors.affiliation: The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Chan Yun
authors.initials: CY
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Se Woong
authors.initials: SW
authors.lastname: Kang
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.|Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
mesh_terms: D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009749:Nutrition Surveys; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000453:epidemiology; D056910:Republic of Korea / Q000453:epidemiology; D012165:Retinal Ganglion Cells / Q000473:pathology*; D019371:Topography, Medical
keywords: Korea National Health and Nutrition Examination Survey; optic disc torsion; peripapillary atrophy; primary open-angle glaucoma; retinal nerve fiber layer defect