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 in n ormal-tension glaucoma (NTG). 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 tenses. Results: No significant differences were observed between the two groups in mean age, mean deviation (MD). and pattern standard deviation (PSD) measur ed 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<.01) in the POAG group and y = 0.59x + 0.6 (r=0.81, P<.001) in the NTG group. Although the average MD measured by FDT was significantly lower in t he POAG group than in the NTG group (P<.05), no significant difference was found in average PSD between the two groups. In early glaucoma cases (MID < greater than or equal to> -5 dB by HFA), a larger proportion of cases in th e POAG group than in the NTG group had lower significance level of MID dete rmined by FDT than by HFA (P<.02). At many test points on the temporal peri phery in the FDT. the mean sensitivity was lower in the POAG group than in the NTG group, whereas no significant differences among HFA test points wer e observed. Conclusions: Frequency doubling technology detected visual field abnormalit ies in POAG cases more sensitively than in NTG cases. This finding indicate s that the pathogenesis of My-cell damage is rather different in POAG and N TG. Jpn J Ophthalmol 2001;45:503-509 (C) 2001 Japanese Ophthalmological Soc iety.