title: Relationship between lamina cribrosa displacement and trans-laminar pressure difference in papilledema.
abstract: OBJECTIVE
  The purpose of this study was to describe morphological changes in lamina cribrosa (LC), prelaminar tissue thickness (PTT) and Bruch's membrane opening (BMO) in eyes affected by papilledema and correlate them with trans-LC-pressure difference (TLCD).
  
  
  METHODS
  This was a prospective study, including twelve eyes newly diagnosed of papilledema. Eyes underwent scanning with Spectralis-OCT with enhanced depth imaging to compare BMO, anterior LC surface position (LC depth-LCD-) and PTT before and after oedema resolution. Correlation analysis between these parameters and TLCD was performed.
  
  
  RESULTS
  TLCD inversely correlated with LCD at baseline and directly with LC reversal movement after lowering cerebrospinal fluid pressure (CSFP) (ρSpearman:-0.739, p = 0.006; ρSpearman:0.844, p = 0.001 respectively). At onset, RNFL thickening and BMO were significantly larger in eyes with TLCD > -9.2 mmHg (group 2) compared with TLCD < -9.2 mmHg (group 1) [p = 0.007, p = 0.041 respectively]. A significant RNFL and BMO shrinking were observed, but they were significantly larger in group 2. The magnitude of LC displacement following oedema resolution was significantly larger and in the opposite direction in group 2 vs group 1 (-68.7 μm vs 19.5 μm, p = 0.016). TLCD correlated with RNFL thickening at baseline (ρSpearman:0.667, p = 0.018) and with RNFL thinning at last visit (ρSpearman:0.673, p = 0.017). TLCD correlated with mean deviation (MD) (ρSpearman:0.712, p = 0.014) and visual field index (VFI) (ρSpearman:-0.657, p = 0.028) at onset. MD and VFI were worse in group 2.
  
  
  CONCLUSIONS
  LC position was significantly related to TLCD in papilledema. Eyes with higher TCLD showed significantly larger backward LC movement, BMO shrinking and RNFL thinning after lowering CSFP compared with eyes with lower TLCD, where LC movement occurred in the opposite direction.
authors.affiliation: Department of Ophthalmology, Hospital Universitario Ramón y Cajal, Carretera de Colmenar Viejo, km. 9.100, 28034, Madrid, Spain. jmontesinos86@hotmail.com.|Qvision, Department of Ophthalmology, Hospital Vithas Virgen del Mar, Almería, Spain. jmontesinos86@hotmail.com.
authors.forename: Javier
authors.identifier: http://orcid.org/0000-0002-3593-321X
authors.initials: J
authors.lastname: García-Montesinos
authors.affiliation: Department of Ophthalmology, Hospital Universitario Ramón y Cajal, Carretera de Colmenar Viejo, km. 9.100, 28034, Madrid, Spain.
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Muñoz-Negrete
authors.affiliation: Department of Ophthalmology, Hospital Universitario Ramón y Cajal, Carretera de Colmenar Viejo, km. 9.100, 28034, Madrid, Spain.
authors.forename: Victoria
authors.initials: V
authors.lastname: de Juan
authors.affiliation: Department of Ophthalmology, Hospital Universitario Ramón y Cajal, Carretera de Colmenar Viejo, km. 9.100, 28034, Madrid, Spain.
authors.forename: Gema
authors.initials: G
authors.lastname: Rebolleda
mesh_terms: D000328:Adult; D016570:Bruch Membrane / Q000473:pathology*; D005260:Female; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D009412:Nerve Fibers / Q000473:pathology; D009898:Optic Disk / Q000473:pathology*; D010211:Papilledema / Q000175:diagnosis / Q000503:physiopathology*; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence / Q000379:methods*; D014794:Visual Fields
keywords: Bruch’s membrane opening; Enhanced depth imaging; Lamina cribrosa; Papilledema; Trans-laminar pressure difference