title: Biometric features of peripapillary atrophy beta in eyes with high myopia.
abstract: OBJECTIVE
  To evaluate peripapillary atrophy β (PPA-β) characteristics in highly myopic eyes, using simultaneous confocal scanning laser ophthalmoscopy (cSLO) and enhanced spectral-domain optical coherence tomography (SD-OCT).
  
  
  METHODS
  The authors retrospectively analyzed 61 highly myopic (≥ -6.0 D) eyes without myopic retinopathy. cSLO fundus images were used to measure the distances from the foveal center to the temporal and nasal margins of the PPA-β zone; horizontal cross-sectional SD-OCT images, to determine the position where the inner plexiform layer (IPL) terminates within the PPA-β zone; and A-mode ultrasonography, to measure axial length.
  
  
  RESULTS
  The distance from the foveal center to the PPA-β zone temporal margin (2.68-4.39 mm) correlated with the circumferential extent of PPA-β (P <0.001, r = -0.49). The distance from the foveal center to the nasal margin (3.41-5.60 mm) correlated with the ovality index of the optic disc (P <0.001, r = -0.51) and with the axial length (P <0.05, r = 0.26). PPA-β zone width (0.20-2.05 mm) correlated with the circumferential extent of PPA-β (P <0.001, r = 0.42), ovality index of the optic disc (P <0.001, r = -0.68), and axial length (P <0.05, r = 0.32). The IPL termination within the PPA-β zone was significantly closer to the optic disc when the circumferential extent of PPA-β was large (P <0.01, r = 0.36).
  
  
  CONCLUSIONS
  Interindividual variations in biometric features of PPA-β in highly myopic eyes showed different associations with axial length, degree of disc ovality, and circumferential extent of PPA-β.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan. a-nonaka@pb3.so-net.ne.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nonaka
authors.forename: Masanori
authors.initials: M
authors.lastname: Hangai
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Akagi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Mori
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nukada
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakano
authors.forename: Nagahisa
authors.initials: N
authors.lastname: Yoshimura
mesh_terms: D000328:Adult; D000368:Aged; D001284:Atrophy / Q000473:pathology; D001699:Biometry / Q000379:methods*; D005260:Female; D005584:Fovea Centralis / Q000473:pathology*; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009216:Myopia / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D012189:Retrospective Studies; D041623:Tomography, Optical Coherence; D055815:Young Adult