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

Abstract

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.