OBJECTIVE: To compare the differences in optic disc configuration with different stages of visual field loss in normal-tension glaucoma. DESIGN: Interocular pairwise comparisons. SETTING: Glaucoma clinic of a teaching hospital. PATIENTS: Thirteen patients with normal-tension glaucoma and asymmetric visual field loss of at least 2.5 dB in the mean defect of the visual field indexes. INTERVENTIONS: Areas under the optic disc profiles mapped from values for radial sections of the optic disc measured at intervals of 30 degrees and expressed as percentages of the area of a rectangle were obtained from stereophotographs with a computerized image analysis system. Visual fields were tested with automated perimetry (OCTOPUS), using program G1. MAIN OUTCOME MEASURE: Correlation analyses between the interocular differences in the areas under the optic disc profile and the interocular differences in the visual field indexes. RESULTS: The correlation coefficients between the interocular differences in mean defect and those of the area under the optic disc profile in the superior to temporal sections ranged from -.71 to -.61 (.007 < P < .028). The interocular differences in loss variance correlated with the differences in the area under the optic disc profile in the superior section (r = -.61, P = .0252). CONCLUSION: The differences in visual field loss between the two eyes in normal-tension glaucoma appear mainly to reflect morphometric changes in the superior half of the optic disc.
OBJECTIVE: To compare the differences in optic disc configuration with different stages of visual field loss in normal-tension glaucoma. DESIGN: Interocular pairwise comparisons. SETTING:Glaucoma clinic of a teaching hospital. PATIENTS: Thirteen patients with normal-tension glaucoma and asymmetric visual field loss of at least 2.5 dB in the mean defect of the visual field indexes. INTERVENTIONS: Areas under the optic disc profiles mapped from values for radial sections of the optic disc measured at intervals of 30 degrees and expressed as percentages of the area of a rectangle were obtained from stereophotographs with a computerized image analysis system. Visual fields were tested with automated perimetry (OCTOPUS), using program G1. MAIN OUTCOME MEASURE: Correlation analyses between the interocular differences in the areas under the optic disc profile and the interocular differences in the visual field indexes. RESULTS: The correlation coefficients between the interocular differences in mean defect and those of the area under the optic disc profile in the superior to temporal sections ranged from -.71 to -.61 (.007 < P < .028). The interocular differences in loss variance correlated with the differences in the area under the optic disc profile in the superior section (r = -.61, P = .0252). CONCLUSION: The differences in visual field loss between the two eyes in normal-tension glaucoma appear mainly to reflect morphometric changes in the superior half of the optic disc.