title: Optic nerve head and peripapillary morphometrics in myopic glaucoma.
abstract: OBJECTIVE
  To investigate morphological characteristics of optic nerve head and peripapillary region with myopia and glaucoma.
  
  
  METHODS
  Ten normal and 17 glaucomatous myopic participants were imaged with a custom 1060-nm swept-source optical coherence tomography system. The three-dimensional images were processed and segmented for inner limiting membrane (ILM), posterior border of retinal nerve fiber layer (RNFL), Bruch's membrane (BM), and posterior border of choroid. Seven shape parameters were measured: nerve fiber layer (NFL) thickness; Bruch's membrane opening (BMO) area, eccentricity, and planarity; BMO and BM depths; and choroidal thickness. The results were analyzed by group and regional sector, and multiple regression was performed on each shape parameter with age, axial length, and glaucoma severity, measured by mean deviation (MD).
  
  
  RESULTS
  Bruch's membrane opening area (P < 0.001), eccentricity (P = 0.025), and planarity (P = 0.019) were correlated with axial length but not with MD, such that larger, more elliptical, and less planar BMO was associated with longer axial length. Several BMOs displayed a saddle-like shape configuration whose orientation appeared to be aligned with that of the BMO ellipse. All BM showed posterior deformation toward BMO such that BM closer to BMO was more posterior than that farther from BMO. Bruch's membrane depth was correlated with axial length (P = 0.014) and MD (P = 0.040) in intersubject regression, and BMO depth (P = 0.003) and BM depth (P = 0.006) were correlated with MD in intereye regression. Bruch's membrane depth was also associated with age. Choroidal thickness was negatively correlated with age (P = 0.001) and with axial length to a smaller degree (P = 0.034), but not with glaucoma severity.
  
  
  CONCLUSIONS
  Axial length was a significant factor in BMO and BM shape in normal and glaucomatous myopic subjects. Posterior deformation of BM was observed in all eyes and significantly associated with functional glaucomatous damage and age.
authors.affiliation: School of Engineering Science, Simon Fraser University, Burnaby, British Columbia, Canada.
authors.forename: Sieun
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Sherry X
authors.initials: SX
authors.lastname: Han
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Mei
authors.initials: M
authors.lastname: Young
authors.affiliation: School of Engineering Science, Simon Fraser University, Burnaby, British Columbia, Canada.
authors.forename: Mirza Faisal
authors.initials: MF
authors.lastname: Beg
authors.affiliation: School of Engineering Science, Simon Fraser University, Burnaby, British Columbia, Canada.
authors.forename: Marinko V
authors.initials: MV
authors.lastname: Sarunic
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Mackenzie
mesh_terms: D000328:Adult; D005901:Glaucoma / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D021621:Imaging, Three-Dimensional; D007429:Intraocular Pressure; D008875:Middle Aged; D009216:Myopia / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D009898:Optic Disk / Q000473:pathology*; D012029:Refraction, Ocular; D012165:Retinal Ganglion Cells / Q000473:pathology*; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence
keywords: ONH; glaucoma; image analysis; myopia; shape analysis