Poor performance in smooth pursuit and antisaccadic eye-movement tasks in healthy siblings of patients with schizophrenia

This study examines the area of eye movement dysfunctions as an indicator o f vulnerability to schizophrenia. Eye movement performance was investigated with three different paradigms: Smooth Pursuit Eye Movements (SPEM); Visua lly Guided Saccades (VGS); and Antisaccades (AS) in 21 clinically stable pa tients with schizophrenia, 21 of their healthy, biological full siblings an d 21 healthy control subjects. The three groups did not differ on VGS perfo rmance, whereas both patients and their siblings showed lower SPEM gain, an increased catch-up Saccades (CUS) rate, reduced AS accuracy and an increas ed number of AS errors in comparison to control subjects. In addition, pati ents with schizophrenia exhibited increased AS latency. Among the patients with schizophrenia, eye movement abnormalities did not correlate with age, gender, clinical state or duration of illness. These data suggest that abno rmalities of SPEM and AS may represent neurobiological markers of the vulne rability to schizophrenia in individuals at high genetic risk for the disea se. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.