title: Evaluation of changes in retinal nerve fiber layer thickness and visual functions in cases of optic neuritis and multiple sclerosis.
abstract: BACKGROUND
  Retinal nerve fiber layer (RNFL) thinning has been demonstrated in cases of optic neuritis (ON) and multiple sclerosis (MS) in Caucasian eyes, but no definite RNFL loss pattern or association with visual functions is known in Indian eyes.
  
  
  OBJECTIVE
  To evaluate RNFL thickness in cases of ON and MS, and to correlate it with visual function changes in Indian patients.
  
  
  METHODS
  Cross-sectional case-control study at a tertiary level institution.
  
  
  METHODS
  Cases consisted of patients of (i) typical ON without a recent episode (n = 30:39 ON eyes and 21 fellow eyes), (ii) MS without ON (n = 15;30 eyes) while the controls were age-matched (n = 15; 30 eyes). RNFL thickness was measured using the Stratus 3 °CT. The visual functions tested included the best-corrected visual acuity (BCVA), contrast sensitivity, stereopsis, visual evoked responses, and visual fields.
  
  
  METHODS
  Intergroup analysis was done using ANOVA and Pearson's correlation coefficient used for associations.
  
  
  RESULTS
  RNFL thickness was reduced significantly in the ON and MS patients compared to the controls (P-0.001). Maximum loss is in the temporal quadrant. Lower visual function scores are associated with reduced average overall RNFL thickness. In ON group, RNFL thinning is associated with severe visual field defects while contrast sensitivity has strongest correlation with RNFL in the MS group.
  
  
  CONCLUSIONS
  RNFL thickness is reduced in ON and MS cases in a pattern similar to Caucasians and is associated with the magnitude of impairment of other visual parameters. Contrast sensitivity and stereoacuity are useful tests to identify subclinical optic nerve involvement in multiple sclerosis.
authors.affiliation: Neuro-Ophthalmology Services, Dr Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India.
authors.forename: Rohit
authors.initials: R
authors.lastname: Saxena
authors.forename: Gopal
authors.initials: G
authors.lastname: Bandyopadhyay
authors.forename: Digvijay
authors.initials: D
authors.lastname: Singh
authors.forename: Sumit
authors.initials: S
authors.lastname: Singh
authors.forename: Pradeep
authors.initials: P
authors.lastname: Sharma
authors.forename: Vimla
authors.initials: V
authors.lastname: Menon
mesh_terms: D000328:Adult; D015350:Contrast Sensitivity; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D009412:Nerve Fibers / Q000473:pathology*; D009900:Optic Nerve / Q000473:pathology*; D009902:Optic Neuritis / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D011379:Prognosis; D012720:Severity of Illness Index; D041623:Tomography, Optical Coherence; D015348:Vision, Binocular; D014794:Visual Fields; D055815:Young Adult