title: Effect of refractive status on peripapillary retinal nerve fibre layer thickness: a study by RTVue spectral domain optical coherence tomography.
abstract: OBJECTIVE
  To evaluate the influence of axial length on retinal nerve fibre layer (RNFL) thickness in myopic, hyperopic and emmetropic eyes by spectral domain optical coherence tomography (OCT).
  
  
  METHODS
  Subjects were divided into three groups: myopic (n=35), emmetropic (n=30) and hyperopic eyes (n=33). RNFL thickness was obtained from all octametric section parameters by RTVue OCT. Axial length and spherical equivalent values were determined for all patients.
  
  
  RESULTS
  RNFL thickness values, except for lower and upper nasal sectors, were thinner in the myopic eyes than in the hyperopic eyes. Average RNFL thickness and the RNFL thicknesses of the superotemporal, superonasal, inferotemporal and lower temporal sectors were significantly different between the myopic and emmetropic eyes, and average RNFL thickness and the RNFL thicknesses of the upper temporal and inferonasal sectors were significantly different between the hyperopic and emmetropic eyes. The average peripapillary RNFL thickness had a negative correlation with axial length (r=-0.741, p<0.001). However, after correction of the magnification effect, the significant differences disappeared.
  
  
  CONCLUSIONS
  We have shown that axial length/refractive status affected the peripapillary RNFL thickness profile measured by RTVue OCT. To make a correct diagnosis for glaucoma, either the axial length-induced magnification effect should corrected by ophthalmologists or the RTVue OCT database should be improved by taking axial length into account.
authors.affiliation: Department of Ophthalmology, Recep Tayyip Erdoğan University Medical School, Rize, Turkey. veysioner@gmail.com
authors.forename: Veysi
authors.initials: V
authors.lastname: Oner
authors.forename: Veysel
authors.initials: V
authors.lastname: Aykut
authors.forename: Mehmet
authors.initials: M
authors.lastname: Tas
authors.forename: Mehmet Fuat
authors.initials: MF
authors.lastname: Alakus
authors.forename: Yalçin
authors.initials: Y
authors.lastname: Iscan
mesh_terms: D000293:Adolescent; D000328:Adult; D058452:Axial Length, Eye / Q000503:physiopathology; D001369:Axons / Q000473:pathology*; D058453:Emmetropia / Q000502:physiology; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology*; D009898:Optic Disk / Q000473:pathology*; D012029:Refraction, Ocular; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence