title: Optic Nerve Head Histopathology in High Axial Myopia.
abstract: OBJECTIVE
  To describe particularities of the optic nerve head of axially highly myopic eyes.
  
  
  METHODS
  Measurements were obtained from enucleated globes and from population-based studies.
  
  
  RESULTS
  Morphologic optic disc particularities in high axial myopia included enlarged disc size (secondary macrodisc), widening and temporal translocation of the papillary Bruch's membrane (BM) opening, parapapillary gamma and delta zone, elongation and thinning of lamina cribrosa and peripapillary scleral flange, steeper translamina cribrosa pressure gradient, decreased peripapillary choroid thickness, longer distance between peripapillary arterial circle and optic disc, optic cup flattening, presumably a stretching of the lamina cribrosa pores, and peripapillary intrachoroidal cavitations. These changes may be explained by growth of new BM in the retroequatorial region in the process of emmetropization or myopization as "overshooting" of the emmetropization process.
  
  
  CONCLUSIONS
  The intrapapillary and parapapillary changes in the highly myopic optic nerve head may be reason for the increased susceptibility for glaucomatous optic nerve damage in high axial myopia. The widening of the papillary BM opening and the potential shift of the optic nerve head's 3 layer into temporal direction, both potentially leading to the development of parapapillary gamma zone may be of interest for elucidating the process of emmetropization/myopization.
authors.affiliation: *Beijing Ophthalmology and Visual Science Key Lab, Beijing Tongren Eye Center, Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China †Department of Ophthalmology, Medical Faculty Mannheim of the Ruprecht-Karls-University of Heidelberg, Mannheim, Germany ‡Department of Ophthalmology and Visual Science, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Jost B
authors.initials: JB
authors.lastname: Jonas
authors.forename: Kyoko
authors.initials: K
authors.lastname: Ohno-Matsui
authors.forename: Songhomitra
authors.initials: S
authors.lastname: Panda-Jonas
mesh_terms: D000328:Adult; D058452:Axial Length, Eye / Q000473:pathology*; D016570:Bruch Membrane; D002829:Choroid / Q000473:pathology; D015353:Eye Enucleation; D005260:Female; D005901:Glaucoma / Q000473:pathology; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D047728:Myopia, Degenerative / Q000473:pathology*; D009898:Optic Disk / Q000473:pathology*; D012590:Sclera / Q000473:pathology; D014019:Tissue Donors