title: Factors determining the peripapillary retinal nerve fiber distribution.
abstract: OBJECTIVE
  To evaluate the influence of the arrangement of the retinal vessels and other ocular features on the peripapillary retinal nerve fiber layer (RNFL) distribution.
  
  
  METHODS
  Fifty normal eyes were included in the study. Axial length (AL), spherical equivalent of the refractive error, and central corneal thickness (CCT) were measured. The interpeak distance of the peripapillary RNFL thickness; the angle between the superior temporal (ST) and inferior temporal (IT) retinal veins; and the average peripapillary RNFL thickness were obtained from the printout results of the spectral-domain optical coherence tomography. The distance from the optic disc center to the foveola and the ratio of distance to disc width were measured from fundus photographs. All measurements were evaluated for correlations among one another and multiple regression analysis and factor analysis was used to determine how ocular factors independently related to the RNFL distribution.
  
  
  RESULTS
  As the AL became longer (P=0.033), and the angle between the ST and IT veins became smaller (P<0.001), the 2 peaks of the peripapillary RNFL thickness moved farther apart. In multiple regression analysis, angle between the ST and IT veins (β=-0.587, P<0.001) and CCT (β=-0.275, P=0.011) were significantly related to interpeak distance of the peripapillary RNFL.
  
  
  CONCLUSIONS
  Decreasing angle between the IT and ST veins, thinner CCT, and increasing AL all appeared to increase the separation of the RNFL peaks. Inter-vessel polar angle affected more on determining the location of the peak in RNFL thickness map. These factors might be used to optimize normative data of the peripapillary RNFL.
authors: *Glaucoma Clinic, HanGil Eye Hospital, Incheon †Department of Ophthalmology and Visual Science, Seoul St. Mary's Hospital, Korea.
authors: Hye Jin
authors: HJ
authors: Chung
authors: Chan Kee
authors: CK
authors: Park
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D058452:Axial Length, Eye / Q000033:anatomy & histology; D005260:Female; D005584:Fovea Centralis; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers; D009898:Optic Disk / Q000033:anatomy & histology*; D012030:Refractive Errors; D012165:Retinal Ganglion Cells / Q000166:cytology*; D012171:Retinal Vessels / Q000033:anatomy & histology*; D041623:Tomography, Optical Coherence / Q000379:methods; D014792:Visual Acuity; D055815:Young Adult