title: Cup-to-disc and arteriole-to-venule ratios in preterm birth.
abstract: OBJECTIVE
  To investigate the influence of preterm birth on the optic disc and retinal vessels by measurements of cup-to-disc (C/D) ratio and arteriole-to-venule (A/V) ratio.
  
  
  METHODS
  Eighty-three eyes of 42 preterm births were included. In the age- and sex-matched control group, 83 eyes of 42 full-term births were used. Fundus color photographs were taken. ImageJ software was used to calculate C/D and A/V ratios from the fundus images.
  
  
  RESULTS
  Fundus photographs were taken at 8.01 ± 2.22 years of age for the preterm group and 8.01 ± 2.13 years of age for the control group. The mean gestational age of the preterm group was 27(4)/7 weeks (range, 24-34 weeks). The preterm group had significantly larger C/D ratio and smaller A/V ratio (mean ± standard deviation: 0.46 ± 0.12 and 0.59 ± 0.08, respectively) than the control group (0.36 ± 0.07 and 0.68 ± 0.07, respectively) after spherical equivalent refractive error was adjusted.
  
  
  CONCLUSIONS
  Preterm birth is significantly associated with larger C/D ratio and smaller A/V ratio. These findings show the effect of preterm birth on the development of optic disc and retinal vessel development.
authors.affiliation: Laboratory of Vascular Biology and Stem Cells, Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea.|Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: J
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: D Y
authors.initials: DY
authors.lastname: Choi
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: K-A
authors.initials: KA
authors.lastname: Park
authors.affiliation: Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
authors.forename: S Y
authors.initials: SY
authors.lastname: Oh
mesh_terms: D001160:Arterioles / Q000033:anatomy & histology; D016022:Case-Control Studies; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D005654:Fundus Oculi; D005865:Gestational Age; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D009898:Optic Disk / Q000033:anatomy & histology*; D010781:Photography; D012030:Refractive Errors; D012171:Retinal Vessels / Q000033:anatomy & histology*; D012178:Retinopathy of Prematurity / Q000175:diagnosis*; D012189:Retrospective Studies; D014699:Venules / Q000033:anatomy & histology