Background. Previous studies of oculomotor dysfunction
schizophrenia have tended to
concentrate on abnormalities of smooth pursuit eye tracking in chronic
medicated patients. We
report the results of a study of smooth pursuit, reflexive and
antisaccade performance in drug naive
and antipsychotic treated first-episode schizophrenic patients.
Methods. Smooth pursuit and saccadic eye movements were recorded
in 36 first-episode
schizophrenic patients and 36 controls matched for age and estimated IQ.
patients were divided into drug-naive (N=17) and antipsychotic
treated groups (N=19).
Results. Smooth pursuit velocity gain was significantly
lower than controls only in the drug-naive
patients. The treated patients did not differ significantly from
either the controls or the untreated
group. In an antisaccade paradigm both treated and drug-naive schizophrenic
an increased number of errors, but only drug-naive patients also demonstrated
an increased latency in initiating correct antisaccades.
Conclusions. These impairments are unlikely to be due to a
generalized deficit in oculomotor
function in the schizophrenic groups, as there were no differences
between the groups in saccadic
metrics on a reflexive saccade task. The results show that both smooth
pursuit and saccadic
abnormalities are present at the onset of schizophrenia and are integral
to the disorder.