+1 Recommend
1 collections
      Are you tired of sifting through news that doesn't interest you?
      Personalize your Karger newsletter today and get only the news that matters to you!

      Sign up

      • Record: found
      • Abstract: found
      • Article: found

      Scanning Laser Polarimetry with Variable Corneal Compensation to Detect Preperimetric Glaucoma Using Logistic Regression Analysis


      Read this article at

          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.


          Background/Aims: To define if a new function improves the capability of the scanning laser polarimetry with variable corneal compensation (GDx-VCC) nerve fiber analyzer in detecting preperimetric glaucoma using 12 retinal nerve fiber layer (RNFL) peripapillary sectors. Methods: Data were obtained in a cross-sectional, hospital-clinic-based study in which 478 eyes from 478 glaucoma suspects were enrolled. All of them underwent ophthalmological examination, static automated perimetry (Humphrey 24-2 Swedish interactive threshold algorithm), optic nerve stereoscopic photography, red-free digital RNFL photography and GDx-VCC examination. The overall intake included 391 normal eyes and 60 preperimetric glaucoma eyes with defects in the fiber layer photographs. Results: The mean values of inferior average, temporal-superior-nasal-inferior temporal average, superior average and the number (nerve fiber indicator) were significantly lower in the eyes with RNFL defects than in the control group, when compared with the obtained linear discriminating function. The area under the curve values for receiver-operating characteristics analysis of the new parameter were 5% better than the best GDx-VCC standard values. Conclusions: Our results confirm that the new function has a better diagnostic reliability in preperimetric glaucoma and confirms the usefulness of morphological diagnosis between normal and early damaged RNFLs.

          Related collections

          Most cited references10

          • Record: found
          • Abstract: found
          • Article: not found

          Evaluation of retinal nerve fiber layer, optic nerve head, and macular thickness measurements for glaucoma detection using optical coherence tomography.

          To compare the ability of optical coherence tomography retinal nerve fiber layer (RNFL), optic nerve head, and macular thickness parameters to differentiate between healthy eyes and eyes with glaucomatous visual field loss. Observational case-control study. Eighty-eight patients with glaucoma and 78 healthy subjects were included. All patients underwent ONH, RNFL thickness, and macular thickness scans with Stratus OCT during the same visit. ROC curves and sensitivities at fixed specificities were calculated for each parameter. A discriminant analysis was performed to develop a linear discriminant function designed to identify and combine the best parameters. This LDF was subsequently tested on an independent sample consisting of 63 eyes of 63 subjects (27 glaucomatous and 36 healthy individuals) from a different geographic area. No statistically significant difference was found between the areas under the ROC curves (AUC) for the RNFL thickness parameter with the largest AUC (inferior thickness, AUC = 0.91) and the ONH parameter with largest AUC (cup/disk area ratio, AUC = 0.88) (P = .28). The RNFL parameter inferior thickness had a significantly larger AUC than the macular thickness parameter with largest AUC (inferior outer macular thickness, AUC = 0.81) (P = .004). A combination of selected RNFL and ONH parameters resulted in the best classification function for glaucoma detection with an AUC of 0.97 when applied to the independent sample. RNFL and ONH measurements had the best discriminating performance among the several Stratus OCT parameters. A combination of ONH and RNFL parameters improved the diagnostic accuracy for glaucoma detection using this instrument.
            • Record: found
            • Abstract: found
            • Article: not found

            Diagnostic accuracy of the GDx VCC for glaucoma.

            To determine the diagnostic accuracy of the GDx VCC in the diagnosis of glaucoma. Prospective, comparative, observational, clinic-based case series. One eye each of 77 healthy subjects and 162 patients with primary open-angle glaucoma of Caucasian racial origin. Healthy subjects had normal visual fields (VFs), healthy-looking optic discs, and intraocular pressures of or =40 were 89.0% and 95.9%, respectively. The multilevel likelihood ratios for glaucoma were 0.07 at NFI values of or =44. At the cutoff level of > or =40, the sensitivities of the NFI for correctly identifying glaucoma patients with mild, moderate, and severe damage were 83.8%, 92.9%, and 90.1%, respectively. The GDx VCC allowed easy, rapid, and accurate discrimination between healthy and glaucomatous eyes. The NFI was the best discriminating parameter. The GDx VCC seems to fulfill criteria for a glaucoma screening device.
              • Record: found
              • Abstract: found
              • Article: not found

              The relationship between standard automated perimetry and GDx VCC measurements.

              To investigate the relationship between retinal light sensitivity measured with standard automated perimetry (SAP) and retardation of the peripapillary retinal nerve fiber layer (RNFL) measured with the GDx VCC (Laser Diagnostic Technologies, Inc., San Diego, CA). Forty-seven healthy subjects and 101 patients with glaucoma were examined with SAP and with the commercially available scanning laser polarimeter GDx VCC, with automated individualized compensation of anterior segment birefringence. Individual visual field test points and peripapillary RNFL retardation measurements were grouped into six corresponding sectors. The correlation between perimetry and GDx VCC measurements was determined, and the relationship between RNFL retardation and perimetry, expressed both in the standard decibel scale and in an unlogged scale, was described with linear regression analysis. A statistically significant correlation was found in most sectors between perimetry and GDx VCC measurements in patients with glaucoma, but not in healthy subjects. A linear relationship was found between the unlogged sensitivities and GDx VCC measurements for the superotemporal and inferotemporal sectors. In the decibel scale, this relationship was curvilinear. GDx VCC measurements of the peripapillary RNFL relate well with functional loss in glaucoma. Based on the observed relationships between function and structure, patients with mild to moderate visual field loss in glaucoma may be better monitored with the GDx VCC and patients who have severe loss, with SAP.

                Author and article information

                S. Karger AG
                July 2009
                20 March 2009
                : 223
                : 4
                : 256-262
                aDepartment of Applied Physics, Science Faculty, Zaragoza University, and bDepartment of Ophthalmology, Miguel Servet University Hospital, Instituto Aragonés de Ciencias de la Salud, Zaragoza, Spain
                209275 Ophthalmologica 2009;223:256–262
                © 2009 S. Karger AG, Basel

                Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher. Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug. Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.

                : 01 June 2007
                : 29 May 2008
                Page count
                Figures: 2, Tables: 6, References: 20, Pages: 7
                Original Paper

                Vision sciences,Ophthalmology & Optometry,Pathology
                Retinal nerve fiber layer,Scanning laser polarimetry with variable corneal compensation,Preperimetric glaucoma


                Comment on this article