Stereoacuity Measurement And Analysis Of The Schizophrenia, Depressed And Anxiety Patients

Normal binocular vision is the process of fusing left and right visual information into a single image and the binocular depth perception is a process of 3D reconstruction based on both monocular and binocular cues. Although there is still a controversy about the development of three-dimensional vision, the 9-year-old children’s stereoscopic vision has reached the adult level which has been recognized by most researchers. Olge et al. reported that 95 percent of the normal population would be expected to have stereo-acuity threholds of at least 40 seconds of arc.It is found that there is an impairment of binocular depth perception in shizophrenia. which leads to the measured stereopsis acuity threshold in the patients is significantly higher than 40 seconds of arc. It further confirms the schizophrenia patients have deficits in early visual information processing system. Most studies to date have focusd on eye movement, visual attention,visual illusion and some other two-dimensional perception in patients with other types of mental disorders,but there is few research directing on the perception of stereopsis.It is meaningful to measure the stereo vision of people with mental illness. First of all, we can gain a better understanding of the actual situation of stereoscopic visual function in patients with mental illness. Secondly, we could find some common damage area in early visual information processing system of the psychotic patients. In our study, we investigated the three-dimensional visual perception mainly in three types of mental illness condition of patients, respectively, in patients with depression, in patients with anxiety disorders and in patients with schizophrenia.We use Titmus test to assess the stereoacuity of patients in unison. Although the computer generated random dot patterns can be very compatible to reduce the impact of monocular cues on the binocular depth perception, but the Titmus stereo chart is easily perceived and understood by subjects and Titmus is still widely used in research on stereoscopic vision. After comparing random dot pattern test and the Titmus test for practical use. we finally chose the Titmus stereopsis test for measuring the level of stereoacuity of the patients.This study is designed to determine the 95% confidence interval of stereoacuity threshold in the population suffering from schizophrenia, depression and anxiety disorders.After comparing the stereo-acuity threshold between different types of people with mental disorders among the population, the study also collected the data of the stereo-acuity threshold in normal population to serve as a reference. In addition,we assess the scale scores of the patients which quantify the severity of the disease and analysis the linear relationship between the scale scores and the stereo-acuity threshold values.Our results show that the mean threshold of stereoacuity in the three groups of patients with mental illness were significantly higher than the normal group and there was no significant correlation between the patient’s stereoacuity thresholds and scale scores. It suggests that not only schizophrenia patients but also the depressed patients and anxiety patients show dysfunction in binocular depth perception.Our research opens a elementary door in the field of studying binocular depth perception in people with mental illness and provides more information to help us understand the mechanism underlying stereoscopic vision.