title: Comparison of visual field severity classification systems for glaucoma.
abstract: OBJECTIVE
  To compare categorical severity classification systems for glaucoma.
  
  
  METHODS
  This cross-sectional study included 1,921 eyes (49.5% right eye) from 1,137 participants from the Diagnostic Innovations in Glaucoma Study and African Descent and Glaucoma Evaluation Study. Standard automated perimetry fields were classified using the: (1) Advanced Glaucoma Intervention Study scoring system (AGIS), (2) Glaucoma Severity Staging system (GSS), and (3) Enhanced Glaucoma Severity Staging system (eGSS). Systems were characterized using the following continuous measures of severity: mean deviation, pattern standard deviation, and visual field index. Classifications between systems and with optic disc stereophotograph assessment were compared (κ) and some stages were consolidated to evaluate severity classification across systems (Wilcoxon test).
  
  
  RESULTS
  Mean deviation, pattern standard deviation, and visual field index were significantly different between GSS and AGIS, and GSS and eGSS in normal and abnormal fields (P<0.005). Agreement between AGIS and eGSS was substantial (κ=0.715±0.012); agreement between GSS and eGSS (κ=0.559±0.014) and AGIS (κ=0.519±0.016) was moderate. eGSS tended to stage abnormal fields most severely followed by GSS and then AGIS (P<0.001).
  
  
  CONCLUSIONS
  The presence of glaucomatous optic neuropathy increases with staging severity for all systems. However, different systems led to different severity staging. Of the systems examined in this study, eGSS may be the better choice for its ease of use for both clinicians and researchers.
authors: Hamilton Glaucoma Center, University of California, San Diego, La Jolla, CA, USA.
authors: Minna
authors: M
authors: Ng
authors: Pamela A
authors: PA
authors: Sample
authors: John P
authors: JP
authors: Pascual
authors: Linda M
authors: LM
authors: Zangwill
authors: Chris A
authors: CA
authors: Girkin
authors: Jeffrey M
authors: JM
authors: Liebmann
authors: Robert N
authors: RN
authors: Weinreb
authors: Lyne
authors: L
authors: Racette
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D005189:False Positive Reactions; D005260:Female; D005902:Glaucoma, Open-Angle / Q000145:classification*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009901:Optic Nerve Diseases / Q000145:classification*; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D014786:Vision Disorders / Q000145:classification*; D014792:Visual Acuity / Q000502:physiology; D058609:Visual Field Tests; D014794:Visual Fields; D055815:Young Adult