ANTIPSYCHOTIC TREATMENT AND EYE MOVEMENT ABNORMALITIES IN SCHIZOPHRENIA

Abstract Background In previous studies of eye movement abnormalities, it was showed that patients with schizophrenia had significant abnormalities in saccade control and smooth pursuit, suggesting that eye movement abnormalities are useful as a biomarker. However, many patients participating in clinical trials are receiving antipsychotic treatment and it is important to examine the effects. Methods Eighty-five patients with schizophrenia were recruited and free-viewing, fixation stability and smooth pursuit tests were performed. First, multiple regression analysis was performed using the obtained parameters as the dependent variables, antipsychotics, illness severity, and duration of illness as independent variables. Secondly, patients were grouped into tertiles by antipsychotic dose (CPZ equivalents), then we conducted a group comparison with each parameter between the three groups. Results A multiple linear regression was calculated to predict each parameter based on CPZ equivalents, illness severity and duration of illness. There was no significance in the free-viewing and fixation stability test after Bonferroni correction. In smooth pursuit test, a significant regression equation was found with the horizontal gain (F (1,81) = 15.1, p < 0.00, R2 = 0.15) and vertical gain (F (1,81) = 12.5, p = 0.02, R2 = 0.12), and both were accounted only for CPZ equivalents. In a group comparison, there were significant effects of the horizontal gain (F (2,80) = 5.32, p = 0.07) and the vertical gain (F (2,80) = 3.31, p = 0.41), but both did not survive Bonferroni correction. Discussion It was found that antipsychotic treatment affects smooth pursuit eye movement. Eye movement abnormalities in schizophrenia can be a useful biomarker from previous studies, but the effects of antipsychotics must be considered.