Relationship between exploratory eye movements and clinical course in schizophrenic patients

Exploratory eye movements are psychophysiological indicators of schizophrenia as well as smooth pursuit eye movements. To investigate whether these eye movements change in accordance with the clinical course of the condition in schizophrenia, exploratory eye movements (number of eye fixations, mean eye scanning length, responsive search score, evaluation of reproduced Fig. 1 and 2) of 28 schizophrenic patients were evaluated in repeat test design, conducted an average of 8 months apart. Subjects were first-medicated schizophrenics, half were outpatients and the remaining half were inpatients at the Neuropsychiatry ward of Tokyo Medical and Dental University Hospital. Exploratory eye movement patterns did not improve despite an improvement in clinical symptoms of schizophrenia. This result and those of previous studies of the exploratory eye movements of schizophrenic patients' families suggest that exploratory eye movements reflect a schizophrenic vulnerability marker. Furthermore, decreased mean eye scanning length (MESL) values were observed in subjects who showed unimproved symptoms, particularly negative symptoms over an extended period of time. The result suggests that a decrease in the MESL value may be the most sensitive indicator in the development of chronicity in schizophrenia.