title: Retinal nerve fiber layer thickness analysis in cases of papilledema using optical coherence tomography – A case control study.
abstract: BACKGROUND
  Papilledema is defined as an optic disk swelling that is secondary to elevated intracranial pressure. Early diagnosis of papilledema can help in early intervention thus preventing visual loss and even death. Optical coherence tomography (OCT) is a non-invasive imaging technique which can detect and quantify diffuse thickening of the retinal nerve fiber layer (RNFL) in eyes with optic disk edema.
  
  
  OBJECTIVE
  To assess the difference in the RNFL thickness in patients with papilledema from controls using OCT and to correlate the RNFL thickness with the degree of papilledema.
  
  
  METHODS
  A case control study was conducted from August 2011 to July 2013 in a tertiary care medical college of south India.
  
  
  METHODS
  All adult patients diagnosed or suspected to have papilledema were included in the study. Disk photographs were graded according to modified Frisen criteria. Fast RNFL protocol on time-domain OCT was used. Cases and controls were compared.
  
  
  METHODS
  RNFL thickness was compared using an independent samples t-test. Correlation between RNFL thickness and modified Frisen scale of papilledema was done using Spearman correlation. GraphPad InStat 3 version was used.
  
  
  RESULTS
  A total of 100 cases and 126 controls were studied. Statistically significant thickening of retinal nerve fiber layer (RNFL) was seen in all quadrants in patients with papilledema as compared to controls. A positive correlation was found between Frisen grading of papilledema RNFL thickness measurements.
  
  
  CONCLUSIONS
  RNFL thickening was mainly in the inferior and superior peripapillary region and was greater in higher grades of papilledema. A strong positive correlation was found between RNFL thickness and the Frisen scale for grading of papilledema. OCT can be included as a routine non-invasive quantitative tool for detection of early papilledema.
authors.affiliation: Department of Ophthalmology, JIPMER, Puducherry 605 006, India. Electronic address: drshashiahuja@gmail.com.
authors.forename: Shashi
authors.initials: S
authors.lastname: Ahuja
authors.affiliation: Department of Ophthalmology, JIPMER, Puducherry 605 006, India.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Anand
authors.affiliation: Department of Medicine, JIPMER, Puducherry 605 006, India.
authors.forename: T K
authors.initials: TK
authors.lastname: Dutta
authors.affiliation: Department of Neurosurgery, JIPMER, Puducherry 605 006, India.
authors.forename: V R
authors.initials: VR
authors.lastname: Roopesh Kumar
authors.affiliation: Department of PSM, JIPMER, Puducherry 605006, India.
authors.forename: Sitanshu Sekar
authors.initials: SS
authors.lastname: Kar
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D019586:Intracranial Hypertension / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology; D009898:Optic Disk / Q000601:surgery*; D010211:Papilledema / Q000601:surgery*; D012160:Retina / Q000601:surgery*; D012165:Retinal Ganglion Cells / Q000473:pathology; D041623:Tomography, Optical Coherence / Q000379:methods; D055815:Young Adult
keywords: Brain tumor; Disk edema; Headache; Optical coherence tomography; Papilledema