title: Interocular asymmetry of visual field defects in primary open angle glaucoma and primary angle-closure glaucoma.
abstract: OBJECTIVE
  To compare the interocular asymmetry in visual field loss of patients with primary open-angle (POAG) and primary angle-closure glaucoma (PACG).
  
  
  METHODS
  Subjects entering a prospective, randomised, controlled trial of intraoperative 5-fluorouracil in glaucoma surgery in Singapore were included. Preoperative visual field testing was performed using automated white-on-white perimetry (24-2 test pattern, threshold program, Mk II, Model 750, Zeiss-Humphrey, San Leandro, CA, USA). A minimum of two tests were required with mean deviation within 2 dB on two tests, fixation losses <20%, false positives <33%, and false negatives <33%. The second field was scored using AGIS II criteria and the 'mean asymmetry score' defined as the mean difference between eyes for both AGIS scores and global indices.
  
  
  RESULTS
  In 230 subjects assessed (128 POAG, 102 PACG), mean interocular asymmetry of visual field loss was greater for the PACG group. The mean AGIS asymmetry scores for total (PACG=9.21+/-6.87 vs POAG=6.48+/-5.58, P=0.001), superior (PACG=4.31+/-3.39 vs POAG=3.35+/-3.13, P=0.035), and inferior (PACG=4.43+/-3.31 vs POAG=2.64+/-2.77, P<0.0001) areas and mean deviation (MD) asymmetry scores (PACG=6.89+/-13.22 vs POAG=1.66+/-16.97, P=0.012) were all significantly different. Interocular correlation of visual field loss for POAG was significant; total AGIS, r=0.27 (P=0.003), superior field AGIS, r=0.24 (P=0.008), inferior field AGIS, r=0.34 (P=0.0001), and MD, r=0.27 (P=0.003). In PACG, there was no significant correlation between eyes; total AGIS, r=-0.02 (P=0.85), superior field AGIS, r=-0.02 (P=0.82), inferior field AGIS, r=-0.17 (P=0.87), and MD, r=0.015 (P=0.89).
  
  
  CONCLUSIONS
  There was a greater asymmetry of visual field loss between eyes, as measured by AGIS scores and MD, in PACG than that in POAG.
authors.affiliation: Singapore National Eye Centre, Singapore.
authors.forename: J-C
authors.initials: JC
authors.lastname: Wang
authors.forename: G
authors.initials: G
authors.lastname: Gazzard
authors.forename: P J
authors.initials: PJ
authors.lastname: Foster
authors.forename: J G
authors.initials: JG
authors.lastname: Devereux
authors.forename: F T S
authors.initials: FT
authors.lastname: Oen
authors.forename: P T K
authors.initials: PT
authors.lastname: Chew
authors.forename: P T
authors.initials: PT
authors.lastname: Khaw
authors.forename: S K L
authors.initials: SK
authors.lastname: Seah
mesh_terms: D000368:Aged; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000150:complications / Q000503:physiopathology*; D005902:Glaucoma, Open-Angle / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014786:Vision Disorders / Q000209:etiology / Q000473:pathology; D058609:Visual Field Tests / Q000379:methods; D014794:Visual Fields