title: Myopia affects retinal nerve fiber layer measurements as determined by optical coherence tomography.
abstract: OBJECTIVE
  To determine whether increasing myopia is associated with thinner peripapillary retinal nerve fiber layer (RNFL) when measured by Stratus optical coherence tomography (OCT).
  
  
  METHODS
  Observational cross-sectional study.
  
  
  METHODS
  Normal subjects with myopia underwent refractometry, axial length measurement (IOL Master), optic nerve examination, and OCT (12 fast RNFL scans/eye). The more myopic eye was chosen as the study eye. Correlation coefficients were calculated for demographic and optic disk characteristics, and degree of myopia.
  
  
  RESULTS
  Mean age (n=27) was 34+/-8 years (range: 23 to 54). Mean cup-to-disk ratio was 0.38 with 41% large and 59% medium disk size. Eight subjects had peripapillary atrophy and 6 had disk tilt. Mean spherical equivalent was -5.40 D (range: -1.25 to -11.25), with mean axial length of 25.65 mm (range: 22.63 to 27.92). No significant associations were found between RNFL thickness and age (P=0.20), sex, disk size, cup-to-disk ratio, tilt, or peripapillary atrophy. RNFL thickness decreased with higher axial length (overall R=-0.70, P<0.001, superior R=-0.60, P=0.001, and inferior R=-0.60, P=0.001), and higher spherical equivalent (overall R=-0.52, P=0.005, superior R=-0.41, P=0.03, and inferior R=-0.45, P=0.02). Overall RNFL thickness decreased 7 mum/1 mm of axial length, and 3 mum/1 D sphere.
  
  
  CONCLUSIONS
  Moderately myopic subjects tend to have thin peripapillary RNFL, mainly at the superior and inferior poles, as measured by Stratus OCT. This phenomenon should be considered when interpreting a glaucoma suspect's Stratus OCT measurements compared with the normative database.
authors.affiliation: Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami School of Medicine, 900 NW 17th Street,Miami, FL 33136, USA.
authors.forename: Frederick M
authors.initials: FM
authors.lastname: Rauscher
authors.forename: Navneet
authors.initials: N
authors.lastname: Sekhon
authors.forename: William J
authors.initials: WJ
authors.lastname: Feuer
authors.forename: Donald L
authors.initials: DL
authors.lastname: Budenz
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology*; D009412:Nerve Fibers / Q000502:physiology*; D012029:Refraction, Ocular / Q000502:physiology; D012165:Retinal Ganglion Cells / Q000502:physiology*; D041623:Tomography, Optical Coherence