title: Nonglaucomatous localized retinal nerve fiber layer defects in Behçet uveitis.
abstract: OBJECTIVE
  To describe nonglaucomatous retinal nerve fiber layer (RNFL) defects in patients with Behçet uveitis.
  
  
  METHODS
  Cross-sectional study and observational case series.
  
  
  METHODS
  We reviewed the clinical photographs of patients with Behçet uveitis (n = 259), ocular toxoplasmosis (n = 120), and multiple sclerosis (MS)-associated uveitis (n = 40) for the presence of localized RNFL defects. Behçet patients with localized RNFL defects were invited to participate in a prospective evaluation including standard automated perimetry, spectral-domain optical coherence tomography (SD OCT), and RNFL thickness analysis. Main outcome measures were the prevalence of localized RNFL defects, perimetric and SD OCT findings, and RNFL thickness analysis.
  
  
  RESULTS
  Sixty-two patients with Behçet uveitis (24%) had localized RNFL defect(s) without any visible scar. Twenty patients (17%) with ocular toxoplasmosis had a localized RNFL defect associated with a retinochoroidal scar in all. None of the MS patients had a localized RNFL defect. Of the 19 patients (24 eyes) with RNFL defect associated with Behçet uveitis who returned for follow-up, there was a corollary thinning on SD OCT B-scan in all and a corresponding visual field defect in 83%. RNFL thickness analysis was within normal limits in 54%, but revealed thinning in the thickness profile scale in 46% and in the pie chart in 21%.
  
  
  CONCLUSIONS
  In Behçet uveitis, localized RNFL defects may be caused by microvascular ischemia at the optic nerve head and/or at the posterior pole and may serve as a helpful ocular diagnostic clue and an indicator of posterior pole involvement, a risk factor for poor visual prognosis.
authors.affiliation: Department of Ophthalmology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey.
authors.forename: Merih
authors.initials: M
authors.lastname: Oray
authors.affiliation: Department of Ophthalmology, Koc University, School of Medicine, Istanbul, Turkey; Department of Ophthalmology, Vehbi Koc Foundation, American Hospital, Istanbul, Turkey.
authors.forename: Sumru
authors.initials: S
authors.lastname: Onal
authors.affiliation: Department of Ophthalmology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey.
authors.forename: Serife
authors.initials: S
authors.lastname: Bayraktar
authors.affiliation: Department of Ophthalmology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey.
authors.forename: Belgin
authors.initials: B
authors.lastname: Izgi
authors.affiliation: Department of Ophthalmology, Istanbul University, Istanbul Faculty of Medicine, Istanbul, Turkey. Electronic address: tutkun@turk.net.
authors.forename: Ilknur
authors.initials: I
authors.lastname: Tugal-Tutkun
mesh_terms: D000328:Adult; D001528:Behcet Syndrome / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis; D009412:Nerve Fibers / Q000473:pathology*; D015995:Prevalence; D011446:Prospective Studies; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014126:Toxoplasmosis, Ocular / Q000175:diagnosis; D014606:Uveitis, Anterior / Q000175:diagnosis*; D058609:Visual Field Tests; D014794:Visual Fields; D055815:Young Adult