Localized Nerve Fiber Layer Defects with Normal Intraocular Pressure and Normal Visual Field

ABSTRACT

PURPOSE: To compare the features of localized nerve fiber layer (NFL) defects between with normal intraocular pressure and normal visual field (Group A) and with early visual field defect in normal-tension glaucoma (Group B). METHODS: This was a retrospective, nonrandomized clinical study in which thirty-two eyes of each group were enrolled. On the NFL photograph, proximity of defect to the fovea (angle alpha) and sum of angular widths of defects (angle beta) were determined. Angle alpha, angle beta and locations of the NFL defect were compared between two groups. The relationship between age and angle alpha and between age and angle beta were examined. Chi square test, student t-test and linear regression analysis were used for statistical analysis. RESULTS: Angle alpha of Group A was larger (68.5 +/- 20.4 degrees) than that of Group B (46.0 +/- 17.1 degrees), and angle beta of Group A was smaller (6.9 +/- 7.6 degrees) than that of Group B (28.0 +/- 21.0 degrees) (p<.05). Angle alpha of Group A decreased as age increased (p<.05), while there was no relationship between age and angle alpha in Group B. Most of NFL defects of Group A were distributed over superior retina but NFL defects of Group B were evenly distributed over superior and inferior retina. CONCLUSIONS: The feature of NFL defect with normal intraocular pressure and normal visual field was different from that of early normal-tension glaucoma. And that cannot be managed as preperimetric stage of normal-tension glaucoma.