Deviated Saccadic Trajectory as a Biometric Signature of Glaucoma

<bold>Purpose: </bold>To investigate whether the trajectories of saccadic eye movements (SEMs) significantly differ between glaucoma patients and controls.<bold>Methods: </bold>SEMs were recorded by video-based infrared oculography in 53 patients with glaucoma and 41 age-matched controls. Participants were asked to bilaterally view 24 degrees-horizontal, 14 degrees-vertical, and 20 degrees-diagonal eccentric Goldmann III-sized stimuli. SEMs were evaluated with respect to the saccadic reaction time (SRT), the mean velocity, amplitude, and two novel measures: departure angle (DA) and arrival angle (AA). These parameters were compared between the groups and the associations of SEM parameters with glaucoma parameters and integrated visual field defects were investigated.<bold>Results: </bold>Glaucoma patients exhibited increased mean SRT, DA, and AA values compared with controls for 14 degrees-vertical visual targets (P = 0.05, P < 0.01, and P < 0.01, respectively). The SRT, DA, and AA were significantly associated with the mean and pattern standard deviations of perimetry and with the mean RNFL thickness by OCT (all P < 0.001). Glaucoma was associated with the AA (P = 0.05) and both the SRT (P = 0.01) and DA (P = 0.04) were associated with integrated visual field defects.<bold>Conclusions: </bold>The saccadic trajectories of glaucoma patients depart in an erroneous path and compensate the disparity by deviating the trajectory at arrival.<bold>Translational relevance: </bold>The initial deviation that we observed (despite continuous exposure to the stimulus) suggests the disoriented spatial perception of glaucoma patients which may be relevant to difficulties encountered daily.