Kaohsiung Journal of Medical Sciences (May 2008)
Correlation Between Quadrant Specific Automatic Visual Field Defect and Retinal Nerve Fiber Layer Thickness as Measured by Scanning Laser Polarimetry in Patients With Primary Open Angle Glaucoma
Abstract
The purpose of this study was to correlate quadrant specific Humphrey visual field mean deviation (MD) with retinal nerve fiber layer (RNFL) thickness as measured by scanning laser polarimetry (GDx), and to determine whether there is a difference in the correlation with visual field defect between the Asian normative database provided by GDx (GDx database) and our native normative database (KMU database). In an age-matched study, a control group of 240 normal eyes underwent GDx. Another 60 eyes with visual field defect due to primary angle glaucoma underwent autoperimetry and GDx examination. First, we compared four GDx measurements between the control and study groups. Next, we divided the visual field into four quadrants (superior, inferior, temporal, nasal) and calculated the MD of each quadrant. We correlated the MD of superior, inferior and overall visual field with RNFL thickness judged by two databases (the GDx Asian internal normative database and the database from our control group). GDx detected abnormal RNFL thickness significantly more accurately when using the KMU database (p = 0.0473 for superior quadrant; p = 0.0074 for inferior quadrant; p = 0.0011 for average thickness) than when using the GDx database. There was no significant difference in the specificity between these two databases. The normal ranges in the GDx internal normative database for Asians are too wide. By using our own GDx normative database, the correlations with MD of autoperimetry were significantly improved. We suggest that every laboratory and clinic establish its own normative database of GDx in Asia.
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