Purpose: To evaluate the usefulness of a new fixation monitoring system called gaze tracking in the perimetry of glaucomatous eyes.
Subjects and method: We studied the visual field of 106 eyes in 106 persons, comprising 74 eyes with open-angle glaucoma and 32 eyes with ocular hypertension. Perimetry was performed using a Humphrey Visual Field Analyzer 740/750 with a 30-2 full threshold program. We used two parameters for gaze tracking: the percentage of the time when the subject's eye deviated from the fixation target more than 3 degrees (G 3) and 6 degrees (G 6). These parameters were assessed in three groups: those with no visual field defect (group N), those with absolute visual field defect including the blind spot (group M 1), and other (group M 0).
Result: The value of G 3 and G 6 were significantly correlated with the fixation loss in groups N and M 0 (p < 0.01). These values were not significantly correlated with the fixation loss in group M 1 (p > 0.1). When the fixation loss was less than 20%, G 3 and G 6 values were significantly higher in group M 1 than in groups N or M 0.
Conclusion: Gaze tracking is a useful fixation monitoring system particularly in the presence of absolute visual field defect including the blind spot.