Abstract
Abstract: :
Purpose:To evaluate the ability of scanning laser polarimetry to detect localized nerve fiber layer (NFL) defects in glaucomatous patients. Methods: The study included 29 eyes of 29 primary open-angle glaucoma patients with localized NFL defects and 43 eyes of 43 normal patients. The localized NFL defects were detected by slit-lamp biomicroscopic examination and/or NFL photography. All patients were submitted to NFL examination using scanning laser polarimetry (GDx - Nerve Fiber Analyzer). Three methods of analysis were used: GDx parameters; NFL thickness measurements in 16 equal sectors around the optic disc (sectorial analysis); and Fourier analysis of the double-hump NFL thickness pattern. Statistical differences in sensitivity at fixed specificities were evaluated. In addition, areas under the receiver operating characteristic (ROC) curves were compared. Results: At a fixed specificity of 91%, the sensibility for the sectorial analysis was 86%, and the area under the ROC curve was .93. For the Fourier analysis the values were 76% and .90, respectively. The sensibilities of GDx parameters (at the same specificity) varied from 21% to 48%. The area under the ROC curves for the sectorial analysis and for the Fourier analysis was significantly greater than the area under the ROC curve for the parameter The Number (0.75)(p<0.001 and p=0.002, respectively). Conclusion: The sectorial analysis and the Fourier analysis of NFL data may be better than GDx parameters in detecting localized nerve fiber layer defects.
Keywords: 430 imaging/image analysis: clinical • 484 nerve fiber layer • 498 optic disc