Fixation Behavior in Primary Open Angle Glaucoma at Early and Moderate Stage Assessed by the MicroPerimeter MP-1

PURPOSE: Using MicroPerimetry MP-1 to assess the fixation behavior in early and moderate primary open angle glaucoma (POAG). METHODS: Thirty-nine early and moderate POAG eyes and 22 normal eyes were enrolled prospectively. The stability and location of the fixation in each subject eye were recorded by the macula 10-degree program of the microperimeter (MP-1). Retinal sensitivity was examined using the G2 program phase 1 of an Octopus 101 perimeter and the macula 10-degree program of the MP-1. The fixation behavior and the retinal sensitivity were compared between POAG and control groups. The correlation between the fixation behavior and the retinal sensitivity was analyzed in POAG patients. RESULTS: : Fixation instability was detected in POAG (P=0.016). It correlated with the mean defect on Octopus perimeter and all the mean macular sensitivity parameters of MP-1, which includes the central 10 degrees (r=0.416, P=0.008), 6 degrees (r=0.401, P=0.011), 2 degrees (r=0.376, P=0.018), inferotemporal (r=0.399, P=0.012) and inferonasal (r=0.387, P=0.015) quadrants of the central 6 degrees. All the POAG patients had a predominantly central fixation. CONCLUSION: Fixation instability manifested in early and moderate POAG eyes, which may be an early sign of POAG.