Contrast Sensitivity in Patients with Schizophrenia of Different Durations of Illness

Abstract

Visual contrastometry was used was used to record contrast sensitivity in healthy subjects and patients with schizophrenia. Gabor elements with spatial frequencies of 0.4, 3.6, and 17.9 cycles/degree were presented. Overall, schizophrenia patients demonstrated lower contrast sensitivity at low and intermediate spatial frequencies than normal subjects. Patients with schizophrenia for less than 10 years showed reduced contrast sensitivity only at low spatial frequencies, while those who had been ill for more than 10 years showed reductions at low, intermediate, and high spatial frequencies. Patients with schizophrenia for less than 10 years and receiving atypical neuroleptics had decreased contrast sensitivity in the low frequency range, whole those receiving typical neuroleptics had decreases in the low and high frequency ranges.