title: A new index to monitor central visual field progression in glaucoma.
abstract: OBJECTIVE
  The visual field index (VFI) summarizes global visual field (VF) data and was developed to monitor glaucoma progression using 24-2 and 30-2 strategies. We applied similar principles and statistical procedures to develop a new parameter, the central field index (CFI), to monitor 10-2 VF progression.
  
  
  METHODS
  Retrospective cohort.
  
  
  METHODS
  Glaucoma patients with paracentral defects seen on 24-2 perimetry and followed up with at least 5 10-2 VF tests.
  
  
  METHODS
  The CFI was developed by calculating age-corrected defect depth at test points obtained during 10-2 examinations. The sensitivities at these points were scored as percentages similar to the method described for the VFI: 100-[(|total deviation|/age-corrected normal threshold) × 100]. A weighting procedure was applied based on published estimates of the occipital cortical spatial magnification. For validation, we performed mixed linear model testing for the association between CFI rates of change (%/year) and known risk factors for glaucoma progression in a population with established glaucoma and at least 5 10-2 VF tests. To determine whether the CFI was affected by cataract, as is known to occur with mean deviation (MD), we conducted a pilot evaluation comparing rates of CFI change in 3 groups: (1) eyes with cataract, (2) pseudophakic eyes, and (3) eyes in which cataract surgery was performed in the middle of the series.
  
  
  METHODS
  Rates of CFI and MD change.
  
  
  RESULTS
  Central field index values were calculated for 176 eyes of 142 patients. The mean rate of CFI change of the entire sample was -1.10%/year (95% confidence interval, -1.03 to -1.16%/year). Elevated intraocular pressure (P<0.001) was associated significantly with faster CFI change, whereas lens status did not influence CFI rates of change (P>0.100) CONCLUSIONS: We developed and validated a new index to monitor central field progression that is minimally affected by the presence or removal of cataract and that correlates significantly with an important risk factor for glaucoma progression. This new index may become useful for glaucoma management, especially when combined with conventional static perimetry strategies.
authors.affiliation: Department of Ophthalmology, New York University School of Medicine, New York, New York; Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, New York. Electronic address: demoraesmd@gmail.com.
authors.forename: Carlos Gustavo
authors.initials: CG
authors.lastname: de Moraes
authors.affiliation: Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, New York.
authors.forename: Rafael L
authors.initials: RL
authors.lastname: Furlanetto
authors.affiliation: Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, New York; Department of Ophthalmology, New York Medical College, Valhalla, New York.
authors.forename: Robert
authors.initials: R
authors.lastname: Ritch
authors.affiliation: Department of Ophthalmology, New York University School of Medicine, New York, New York; Einhorn Clinical Research Center, New York Eye and Ear Infirmary, New York, New York.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Liebmann
mesh_terms: D000368:Aged; D000465:Algorithms; D002386:Cataract / Q000175:diagnosis; D002387:Cataract Extraction; D018450:Disease Progression; D005189:False Positive Reactions; D005260:Female; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009901:Optic Nerve Diseases / Q000175:diagnosis*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014065:Tonometry, Ocular; D014786:Vision Disorders / Q000175:diagnosis*; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields