Abstract
Abstract: :
Purpose: To assess the ability of the GDx with the variable corneal compensator (VCC) to detect glaucomatous damage and to compare it to glaucomatous visual field (VF) defects tested by Humphrey field analyzer (HFA). Methods: Scanning laser polarimetry (SLP) by GDx was performed on glaucoma patients [primary open–angle glaucoma (POAG) and normal tension glaucoma (NTG)]. Healthy age matched subjects served as a control group. Both groups underwent a clinical examination and VF with HFA within two weeks from the GDx examination. Glaucoma damage was defined as CPSD<5% in the VF. A comparison between 4 parameters of the GDx (NFI, TSNIT average, superior and inferior average) and functional parameters from the perimetry were performed. A P < 0.05 was considered statistically significant for the GDx test. A numeric value (NFI) > 30 was considered as suspected glaucomatous damage. Results: Twenty three eyes were included in the glaucoma group and compared to 16 non glaucomatous eyes. Both groups had similar demographic parameters. A NFI>30 had a specificity and sensitivity of 100%. Both the NFI>50 and the TSNIT average (P<0.05) had a sensitivity of 100% but a specificity of about 70%. The GDx superior and inferior average parameters detected focal damage in the VF of 90% of the cases. Conclusions: The GDx with the VCC has a high sensitivity and moderate–high specificity. In all the glaucoma patients there was at least one abnormal GDx parameter. The GDx is a simple and fast test that can be used as a supplementary method to detect early glaucomatous damage.
Keywords: nerve fiber layer • clinical (human) or epidemiologic studies: systems/equipment/techniques • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)