Progression of visual field defects in eyes with different optic disc appearances in patients with normal tension glaucoma

PURPOSE: To investigate the relationship between the optic disc appearance and the progression of visual field defects in eyes with normal tension glaucoma (NTG). METHODS: Two hundred nine patients with NTG, who were being treated with topical antiglaucoma drugs and had been followed for at least 3 years, were studied. The baseline optic disc appearance was classified into 4 types: focal ischemic (FI), myopic glaucomatous (MY), senile sclerotic (SS), and generalized cup enlargement (GE). The progression of the NTG was assessed by the slope of the mean deviations (MDs) obtained from the visual field results collected during the follow-up examinations. The baseline and mean intraocular pressures (IOPs) were also followed. RESULTS: Twenty-seven patients were placed in the FI group, 63 into the MY group, 24 into the SS group, and 43 into the GE group. Fifty-two patients (24.9%) could not be classified. There were no significant differences in the percentage reduction of the IOP among the 4 groups. The MD slope in the GE group (-0.51±0.74 dB/y) was significantly steeper than that in the other groups. Regression analyses showed that the factors most associated with the MD slope were the age in the FI (r, -0.495) and the GE (r=0.496) groups, and the relative reduction of the IOP (r=0.413) in the SS group. None of the factors in the MY group was significantly associated with the MD slope. CONCLUSIONS: The rate of progression of the field defects, the MD slope, in patients with NTG is possibly dependent on the baseline optic disc appearance. Thus, the optic disc appearance may be useful for the management of patients with NTG.