title: Associations between Optic Cup-to-disc Ratio and Systemic Factors in the Healthy Korean Population.
abstract: OBJECTIVE
  To assess the relationships between optic cup-to-disc ratio (CDR) and age, sex, and other demographic and health characteristics in the healthy Korean population.
  
  
  METHODS
  The study design was retrospective and population-based. A total of 28,377 subjects who participated in the Korea National Health and Nutrition Examination Survey between 2008 and 2011 were enrolled in this study. Participants underwent structured interviews as well as systemic and ophthalmic examinations. Patients with glaucoma who were diagnosed using the International Society of Geographical and Epidemiological Ophthalmology classification were excluded. Changes in vertical CDR were examined by age in relation to systemic variables on multiple regression analysis.
  
  
  RESULTS
  The mean vertical CDR was 0.34 ± 0.12. The vertical CDR increased with age from subjects in their 20s to those in their 80s (p < 0.001). The mean CDR in males was significantly higher than that of females (p < 0.001). On multiple regression analysis, the vertical CDR was positively associated with age (p < 0.001), male sex (p < 0.001), diastolic blood pressure (p = 0.009), and intraocular pressure (p < 0.001) but was negatively associated with body mass index (p < 0.001).
  
  
  CONCLUSIONS
  Greater vertical CDR was related to age, male sex, higher diastolic blood pressure, higher intraocular pressure, and lower body mass index in healthy Koreans.
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Yang Jae
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Joon Mo
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Seong Hee
authors.initials: SH
authors.lastname: Shim
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jeong Hun
authors.initials: JH
authors.lastname: Bae
authors.affiliation: Department of Ophthalmology, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
mesh_terms: D017677:Age Distribution; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000175:diagnosis / Q000453:epidemiology*; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D009017:Morbidity / Q000639:trends; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis / Q000453:epidemiology*; D011159:Population Surveillance; D012016:Reference Values; D056910:Republic of Korea / Q000453:epidemiology; D012189:Retrospective Studies; D017678:Sex Distribution; D014065:Tonometry, Ocular
keywords: Cup-to-disc ratio; Korea National Health and Nutrition Examination Survey; Koreans; Population based; Systemic factor