PURPOSE: To compare the results of scanning laser polarimetry of the retinal nerve fiber layer obtained by using the GDx Scanning Laser System® in primary open angle glaucoma (POAG) and nonglaucomatous Brazilian subjects over 40 years, also analyzing the differences between the data obtained from right and left eyes. METHODS: Forty-six POAG patients and 44 normal subjects were enrolled in this study. Retardation data were assessed by the GDx Scanning Laser System®. The medians of the parameters printed in the result were compared in these two groups, separately in the right and left eyes, using Mann-Whitney's test. Also the frequencies of outside normal parameters and quadrants of deviation from normal graph were compared in these two groups, using chi-square or Fisher's exact test. RESULTS: All parameters obtained by GDx differed in a statistically significant way between the two groups, except symmetry for left eyes. The frequency of inferior quadrant with p<5% regarding deviation from normal graph was higher in the glaucomatous group. The most frequent outside normal limits parameters in the glaucomatous group were: maximal modulation, ellipse modulation, superior average and inferior average. All parameters except symmetry and superior/nasal differed between right and left eyes in the nonglaucomatous group. CONCLUSION: The parameters obtained by GDx are different in normal and glaucomatous subjects of that population. There are some parameters that deviate from normal values with a greater frequency in glaucomatous patients. An evident difference between the data of right and left eyes of normal subjects in this group was also observed.
Glaucoma; Nerve fibers; Retina; Ophthalmological diagnostic technics; Perimetry
