title: Prevalence and spatial concordance of visual field deterioration in fellow eyes of glaucoma patients.
abstract: OBJECTIVE
  To examine the prevalence of visual field deterioration in contralateral eyes of patients with worsening open-angle glaucoma and to evaluate the spatial concordance of visual field deterioration between both eyes.
  
  
  METHODS
  One hundred sixteen open-angle glaucoma patients who underwent 8 or more visual field examinations over ≥ 6 years of follow-up were included. The rates of the fast and slow components of visual field decay for each of 52 visual field test locations were calculated with point-wise exponential regression analysis. The spatial concordance of visual field deterioration in contralateral eyes was evaluated with a concordance ratio (calculated as the number of overlapping locations divided by the total number of deteriorating locations) and by comparing the rate of decay in corresponding modified glaucoma hemifield test clusters.
  
  
  RESULTS
  The average visual field mean deviation (± standard deviation [SD]) was -8.5 (± 6.4) dB and the mean (± SD) follow-up time was 9.0 (± 1.6) years. Sixty-three patients had mild damage, 23 had moderate damage, and 30 had severe damage. The mean concordance ratio (± SD) was 0.46 (± 0.32) for the mild group, 0.33 (± 0.27) for the moderate group, and 0.35 (± 0.21) for the severe group. Thirty-one patients (27%) had deterioration in concordant locations (p < 0.05). Visual field deterioration was greater in the superior hemifield than the inferior hemifield (p < 0.05) when evaluated with both the concordance ratio and modified glaucoma hemifield test cluster analysis methods.
  
  
  CONCLUSIONS
  There is only fair spatial concordance with regard to visual field deterioration between the both eyes of an individual. We conclude that testing algorithms taking advantage of inter-eye spatial concordance would not be particularly advantageous in the early detection of glaucomatous deterioration.
authors.affiliation: Siloam Eye Hospital, Seoul, Korea.
authors.forename: Min Kyo
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Siloam Eye Hospital, Seoul, Korea.
authors.forename: Jun Mo
authors.initials: JM
authors.lastname: Lee
authors.affiliation: The Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Esteban
authors.initials: E
authors.lastname: Morales
authors.affiliation: The Jules Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Caprioli
mesh_terms: D000368:Aged; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D013028:Space Perception / Q000502:physiology*; D014786:Vision Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology*
keywords: Point-wise exponential regression analysis; Spatial concordance; Visual field deterioration