COMPARISON OF VISUAL-FIELD DEFECTS BETWEEN NORMAL-TENSION AND PRIMARYOPEN-ANGLE GLAUCOMA IN THE LATE-STAGE OF THE DISEASE

Background: There is a lack of studies focusing on differences in visu al field damage between normal-tension glaucoma (NTG) and primary open -angle glaucoma (POAG) in the late stage of the disease. This problem was addressed in 34 NTG cases and 63 POAG cases with a mean deviation (STATPAC)less than or equal to-15 dB. Age, refraction, mean deviation, best corrected visual acuity and sex ratio showed no significant betw een-group differences. Methods: Total deviation (STATPAC), the differe nce between the measured threshold and the age-corrected normal refere nce at each test point of the Humphrey 30-2 or 10-2 program (TD30 or T D10) was used for pointwise between-group comparisons: (I) difference in the TD30 or TD10 at the examination point due to the difference of disease type was examined using logistic discriminant analysis; (2) a relatively spared point in a given visual field was defined as a test point of TD30 or TD10>mean deviation/3 and the incidence was compared pointwise between the two groups. Further, (TD30-mean TD30) or (TD10-m ean TD30) was used to compare the diffuseness of the visual field dama ge. Results and conclusion: The two methods of pointwise between-group comparison gave similar results. In late-stage disease, the inferior ceco-central field was found to be significantly less depressed in NTG than in POAG. Between-group difference was also suggested in the dama ge in the superior field and the lower Bjerrum area and in the diffuse ness of the visual field damage.