title: The influence of intersubject variability in ocular anatomical variables on the mapping of retinal locations to the retinal nerve fiber layer and optic nerve head.
abstract: OBJECTIVE
  To investigate the influence of intersubject variation in ocular parameters on the mapping of retinal locations to the retinal nerve fiber layer and optic nerve head.
  
  
  METHODS
  One hundred retinal nerve fiber layer (RNFL) bundle photographs from 100 subjects were optimized digitally and single RNFL bundles manually traced back to the ONH where their entry point was noted. A 24-2 visual field (VF) grid pattern was superimposed onto the photographs in order to relate VF test points to intersecting RNFL bundles and their entry angles into the ONH. Axial length, spherical equivalent, the position of the ONH in relation to the fovea, size, orientation, tilt, and shape of the ONH were assessed. Multilevel linear models were generated for predicting the entry angle of RNFL bundles, based on ocular parameters.
  
  
  RESULTS
  A total of 6388 RNFL bundles were traced. The influence of ocular parameters could be evaluated for 33 out of 52 VF locations. The position of the ONH in relation to the fovea was the most prominent predictor for variations in the mapping of retinal locations to the ONH, followed by disc area, axial length, spherical equivalent, disc shape, disc orientation, and disc tilt.
  
  
  CONCLUSIONS
  Mapping of retinal locations to the optic nerve head varies between patients according to a given patient's ocular parameters. By considering these parameters, patient-tailored, structure-function maps can be built and structural and functional measurements can be correlated more accurately. Individualized maps may assist clinicians detecting glaucoma and monitoring glaucomatous progression.
authors.affiliation: National Institute for Health Research NIHR Biomedical Research Center for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom.
authors.forename: Julia
authors.initials: J
authors.lastname: Lamparter
authors.forename: Richard A
authors.initials: RA
authors.lastname: Russell
authors.forename: Haogang
authors.initials: H
authors.lastname: Zhu
authors.forename: Ryo
authors.initials: R
authors.lastname: Asaoka
authors.forename: Takehiro
authors.initials: T
authors.lastname: Yamashita
authors.forename: Tuan
authors.initials: T
authors.lastname: Ho
authors.forename: David F
authors.initials: DF
authors.lastname: Garway-Heath
mesh_terms: D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000166:cytology*; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000166:cytology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D014794:Visual Fields; D055815:Young Adult
keywords: function; structure; variability