[Comparison of detectability of visual field abnormality by frequency doubling technology in primary open-angle glaucoma and normal-tension glaucoma].

PURPOSE

To compare the effectiveness of frequency doubling technology(FDT) in detecting abnormalities in primary open-angle glaucoma(POAG) and normal-tension glaucoma(NTG).

SUBJECTS AND METHODS

Twenty-nine POAG patients (29 eyes) and 27 NTG-patients(27 eyes) were studied. All subjects underwent testing with program C-20 of FDT with appropriate corrective lenses.

RESULTS

No significant differences were observed between the two groups in mean age, mean deviation(MD), and pattern standard deviation(PSD) measured by the Humphrey Field Analyzer(HFA). The correlation between MD values determined by HFA(x) and FDT(y) is represented by y = 0.60x - 2.7 (r = 0.78, p < 0.01) in the POAG group and y = 0.59x + 0.6 (r = 0.81, p < 0.001) in the NTG group. No significant difference was found in the average PSD between the two groups. In early glaucoma cases (MD > or = -5 dB by HFA), a larger proportion of cases in the POAG group than the NTG group had a lower significance level of MD determined by FDT than by HFA (p < 0.02). At many test points on the temporal periphery in FDT the mean sensitivity was lower in the POAG group than in the NTG group; whereas no significant differences among HFA test points were observed.

CONCLUSIONS

FDT detected visual field abnormalities in POAG cases more sensitively than in NTG cases. This finding indicates that the pathogenesis of My-cell damage is different in POAG and NTG.