title: Comparison of the correlations between optic disc rim area and retinal nerve fiber layer thickness in glaucoma and nonarteritic anterior ischemic optic neuropathy.
abstract: OBJECTIVE
  To test whether comparison of the correlation between optic disc rim area and retinal nerve fiber layer thickness (rim-RNFL correlation) can differentiate eyes with nonarteritic anterior ischemic optic neuropathy (NAION) from eyes with open-angle glaucoma (OAG).
  
  
  METHODS
  Prospective cross-sectional study.
  
  
  METHODS
  One hundred and thirteen eyes with OAG and 22 with NAION were included in this study. The rim-RNFL correlation in OAG eyes was analyzed in global and 12-clock-hour parameters using rim areas determined by Heidelberg retina tomography (HRT II) and RNFL thicknesses determined by optical coherence tomography (Cirrus OCT). The eyes with NAION were determined whether to be out of the 95% prediction interval (PI) for the rim-RNFL correlation of OAG in global and clock-hour parameters.
  
  
  RESULTS
  A significant linear rim-RNFL correlation was observed in global and all clock-hour sectors, except the 3-, 4-, and 9-o'clock sectors, in OAG (0.045 < r(2) < 0.64, P < .05, respectively). All eyes with NAION were outside the 95% PI of the rim-RNFL correlation of OAG in at least 1 clock-hour sector in terms of clock-hour parameters, as compared with 63.6% of eyes in terms of global parameter. All NAION eyes (n = 21) with 7- or 11-o'clock involvement had a rim-RNFL correlation outside the 95% PI of OAG for corresponding clock-hour sectors.
  
  
  CONCLUSIONS
  By comparison of the rim-RNFL correlation, eyes with NAION were found to be well differentiated from OAG eyes, especially in clock-hour sectors. It might be an objective approach to discriminate NAION from OAG.
authors.affiliation: Department of Ophthalmology, Kwandong University, Myongji Hospital, Koyang, Korea.
authors.forename: Min Hee
authors.initials: MH
authors.lastname: Suh
authors.forename: Seok Hwan
authors.initials: SH
authors.lastname: Kim
authors.forename: Ki Ho
authors.initials: KH
authors.lastname: Park
authors.forename: Sung Jun
authors.initials: SJ
authors.lastname: Kim
authors.forename: Tae-Woo
authors.initials: TW
authors.lastname: Kim
authors.forename: Seung-Sik
authors.initials: SS
authors.lastname: Hwang
authors.forename: Dong Myung
authors.initials: DM
authors.lastname: Kim
mesh_terms: D001167:Arteritis / Q000175:diagnosis; D003430:Cross-Sectional Studies; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009887:Ophthalmoscopy; D009898:Optic Disk / Q000473:pathology*; D018917:Optic Neuropathy, Ischemic / Q000175:diagnosis*; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence