title: Alterations in the neural and connective tissue components of glaucomatous cupping after glaucoma surgery using swept-source optical coherence tomography.
abstract: OBJECTIVE
  To visualize changes in deep optic nerve head (ONH) structures following glaucoma surgery using (3-dimensional [3D]) swept-source optical coherence tomography (SS-OCT) and to determine the clinical and structural factors associated with postoperative lamina cribrosa (LC) and prelaminar neural tissue (PLT) changes.
  
  
  METHODS
  In this prospective observational case series, SS-OCT thin-sliced datasets of the ONH covering a 3- × 3-mm area comprised of 256 B-scans (interval between scans = ∼12 μm) were obtained before and 3 months after the surgery and evaluated in 73 eyes of 73 patients with glaucoma. Bruch's membrane opening (BMO) and anterior LC boundary were manually delineated by two methods; one in every four B-scans (64 B-scans per eye) and 15 equally spaced horizontal B-scans in BMO area, excluding both ends (interval between scans = 96-120 μm). After former delineation, the point with maximum LC depth among 64 B-scans was automatically calculated, and LC depth and PLT thickness were averaged among 5 points adding 4 points 100 μm apart from this point vertically and horizontally. Associations between the percent change in LC depth and other clinical and structural parameters were tested for statistical analysis.
  
  
  RESULTS
  Lamina cribrosa depth and axial length significantly decreased and PLT thickness significantly increased after surgery. The percent change of maximum LC depth correlated significantly with the percent change of IOP (P = 0.008), baseline LC depth (P = 0.032), and visual field mean deviation (P = 0.035; at the point with maximum LC depth), while the percent change of axial length correlated with IOP reduction (P = 0.002) but not with visual field mean deviation.
  
  
  CONCLUSIONS
  Swept-source optical coherence tomography enables 3D analysis of deep ONH structures, and the change in LC depth after glaucoma surgery have association with IOP change and the severity of glaucomatous optic neuropathy.
authors.affiliation: Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Munemitsu
authors.initials: M
authors.lastname: Yoshikawa
authors.forename: Tadamichi
authors.initials: T
authors.lastname: Akagi
authors.forename: Masanori
authors.initials: M
authors.lastname: Hangai
authors.forename: Hanako
authors.initials: H
authors.lastname: Ohashi-Ikeda
authors.forename: Kohei
authors.initials: K
authors.lastname: Takayama
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morooka
authors.forename: Yugo
authors.initials: Y
authors.lastname: Kimura
authors.forename: Noriko
authors.initials: N
authors.lastname: Nakano
authors.forename: Nagahisa
authors.initials: N
authors.lastname: Yoshimura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003238:Connective Tissue / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005901:Glaucoma / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis* / Q000209:etiology; D011184:Postoperative Period; D011446:Prospective Studies; D041623:Tomography, Optical Coherence / Q000379:methods*; D014130:Trabeculectomy; D055815:Young Adult
keywords: lamina cribrosa; swept-source optical coherence tomography; trabeculectomy; trabeculotomy