title: Repeatability of Spectral Domain Optical Coherence Tomography Measurements in High Myopia.
abstract: The purpose of this study was to compare the repeatability of spectral domain optical coherence tomography (SDOCT) parameters in high-myopic and emmetropic healthy subjects, and to evaluate the influence of axial length on the repeatability of SDOCT parameters in high myopia.
  
  
  
  In a prospective study, 93 eyes of 63 high-myopic subjects (spherical refractive error, -6 to -12 D; median age, 25 y) and 28 eyes of 14 emmetropic (spherical refractive error, 0 D; median age, 30 y) subjects underwent optic nerve head, retinal nerve fiber layer (RNFL), and ganglion cell complex imaging with SDOCT. For the repeatability analysis, 31 eyes of 31 high-myopic subjects and 14 eyes of 14 emmetropic subjects underwent 3 repeated scans in the same session.
  
  
  
  Among the optic nerve head parameters, within-subject coefficient of variation (CVw) measurements of the disc area (0.6% vs. 0.2%), rim area (8.7 vs. 2.8), and rim volume (16.7 vs. 8.9) were significantly larger (worse) in high-myopic compared with the emmetropic subjects. CVw measurements of all RNFL (range, 1.7 to 22.4) and ganglion cell complex (range, 1.8 to 2.5) parameters in high-myopic subjects were comparable to that in emmetropic subjects (2.4 to 24.0 and 1.7 to 2.0, respectively). Axial length significantly affected the CVw of nasal (coefficient, 0.01; P=0.04) and average RNFL (coefficient, 0.004; P=0.001) parameters but not that of the other SDOCT parameters.
  
  
  
  Repeatabilities of most of the SDOCT parameters in high-myopic subjects were good and comparable to that of emmetropic subjects. This suggests that SDOCT can be useful for following up high-myopic glaucoma patients to detect progression.
authors.affiliation: VST Glaucoma Center, L V Prasad Eye Institute, Banjara Hills, Hyderabad, India.
authors.forename: Harsha L
authors.initials: HL
authors.lastname: Rao
authors.forename: Addepalli U
authors.initials: AU
authors.lastname: Kumar
authors.forename: Sampath R
authors.initials: SR
authors.lastname: Bonala
authors.forename: Kadam
authors.initials: K
authors.lastname: Yogesh
authors.forename: Bodduluri
authors.initials: B
authors.lastname: Lakshmi
mesh_terms: D000328:Adult; D058452:Axial Length, Eye / Q000473:pathology; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D047728:Myopia, Degenerative / Q000150:complications*; D009412:Nerve Fibers / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods / Q000592:standards*; D014065:Tonometry, Ocular; D058609:Visual Field Tests; D055815:Young Adult