Smooth pursuit eye movements of patients with schizophrenia and affective disorder during clinical treatment

Background Smooth pursuit eye movement dysfunctions are considered a biological indicator for vulnerability to schizophrenia. This study examines test-retest stability of specific eye movement variables such as velocity gain and different saccadic categories. Methods Smooth pursuit eye movements of 27 schizophrenic patients and 30 patients with major depression were examined three times during clinical treatment using high-resolution infrared oculography. Forty-one normal controls were retested after four weeks. Results Intraclass correlation coefficients as a measure for retest-stability were highly significant in each group for all time-points, except for anticipatory saccades in schizophrenics. No significant correlations were found between psychopathological status, neuroleptic medication and eye movement variables. Conclusions Our results indicate that the most important measures of eye tracking performance in psychiatric patients are not significantly influenced by neuroleptic medication or clinical state and are stable across time.