title: Central Field Index Versus Visual Field Index for Central Visual Function in Stable Glaucoma.
abstract: OBJECTIVE
  To compare the variability of central field index (CFI) versus visual field index (VFI) in stable glaucoma with central fixation involvement.
  
  
  METHODS
  For this retrospective study, we identified multiple visual fields (VFs) of patients with repeatable central fixation involvement on Humphrey VFs (24-2 and 10-2 program) which were stable (clinically and on VFs) over a very short period of 2 to 3 months. The VFI and CFI were calculated as described in earlier reports. We graded the fields as early [mean deviation (MD)>-6 dB], moderate (-6.1 to -12 dB), and severe glaucoma (<-12 dB) based on MD on 24-2 program. The variability of CFI and VFI between visits and across different severity of glaucoma was compared. Relation of the divergence to field indices and clinical parameters were assessed.
  
  
  RESULTS
  The intervisit difference for VFI was greater than CFI ranging from -4% to 9% versus -1% to 8% in early (P=0.9), -13% to 18% versus -6% to 17% (P=0.056) in moderate, and -21% to 19% versus -9% to 9% (P<0.001) in severe glaucoma. The CFI within each group had narrower range than VFI with maximum range in severe glaucoma (33% to 95%). The divergence of CFI from VFI started at MD 24-2 beyond (worse) -10 dB. This difference between CFI and VFI was associated significantly with number of points with P<1% on 24-2 (R=80.3%).
  
  
  CONCLUSIONS
  CFI is less variable than VFI in stable eyes with fixation involvement especially in severe glaucoma indicating need for incorporating CFI calculation for monitoring advanced disease in eyes with central defects.
authors.affiliation: Glaucoma Services, LV Prasad Eye Institute, Bhubaneswar, India.
authors.forename: Aparna
authors.initials: A
authors.lastname: Rao
authors.forename: Debananda
authors.initials: D
authors.lastname: Padhy
authors.forename: Harika
authors.initials: H
authors.lastname: Mudunuri
authors.forename: Avik K
authors.initials: AK
authors.lastname: Roy
authors.forename: Sarada P
authors.initials: SP
authors.lastname: Sarangi
authors.forename: Gopinath
authors.initials: G
authors.lastname: Das
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D005260:Female; D005901:Glaucoma / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*; D055815:Young Adult