Discrimination between normal and glaucomatous eyes with scanning laser polarimetry and optic disc topography: A preliminary report

PURPOSE. To test the ability of structural parameters (as measured by scanning laser polarimetry (SLP) software 1.0.12 and confocal scanning laser ophthalmoscopy (CSLO) to discriminate between normal and glaucomatous eyes. METHODS. A total of 112 patients with primary open-angle glaucoma and 88 normal individuals were enrolled in the study. All individuals underwent a thorough ophthalmic evaluation, a 24-2 full threshold Humphrey visual field, SLP with the GDx, and CSLO with the TOPSS. Patients with marked cataract or low vision were excluded from the study. Cut-off points were selected and receiver operator characteristic (ROC) curves were created for each individual CSLO and SLP parameter. Finally, multivariate discriminant formulas were developed in order to achieve a better sensitivity (Se)/specificity (Sp) ratio for the diagnosis of glaucoma, initially separately for each device, and then combining parameters from CSLO and SLP. RESULTS. The mean deviation for the glaucoma group was -10.63 +/- 7.58 dB. Multivariate discriminant formulas resulted in better sensitivity/specificity ratios than any individual parameter, either for CSLO (Se: 90%; Sp: 81%; accuracy: 86%) or SLP (Se: 87%; Sp: 86%; accuracy: 86%). The multivariate formula combining parameters from both devices resulted in an improvement in the ability to diagnose glaucoma. An area under the ROC curve of 0.97 was obtained, with a sensitivity of 93%, a specificity of 91%, and an accuracy of 92%. CONCLUSIONS. The combination of structural parameters derived from CSLO and SLP in a multivariate discriminant formula may enhance the ability to diagnose glaucoma. Further studies investigating a random population are needed in order to test the validity of this formula.