Reliability and Diagnostic Validity of a Novel Visual Disturbance Subjective Experience Scale in Chinese Patients with Schizophrenia

Abstract

Objectives: Visual abnormalities are common among patients with schizophrenia and have been associated with retinal thickness impairment (RTI). A reliable tool for assessing altered visual experiences in this population is not yet available. The objective of this work was to establish a novel scale based on visual perception disturbance (VPD) items extracted from the Bonn Scale for the Assessment of Basic Symptoms (BSABS) and to examine the scale’s reliability and validity in Chinese patients with schizophrenia. Methods: A total of 100 first-diagnosed, non-medicated patients with schizophrenia (FUSCH) and 100 healthy controls (HCs) were enrolled. The reliability of our BSABS-based visual perception subjective experience scale (VPSES), called the BSABS-VPSES, was assessed by calculating the inter-rater correlational coefficient for five psychiatrists’ patient evaluations. The discriminative validity of the BSABS-VPSES was determined by assessing the relationship between VPD symptom scores and RTI severity as determined by optical coherence tomography (OCT) performed by two ophthalmologists. Results: The BSABS-VPSES provided reliable data (Cronbach's a = 0.90), and BSABS-VPSES scores correlated with RTI magnitude (r = 0.88, 0.84, and 0.65, for mild-, moderate-, and severe-grade RTI groups, respectively; all p < 0.05), affirming the scale’s validity. Using the BSABS-VPSES, we found that 67% of FUSCH patients had VPD symptoms, and that 52% of FUSCH patients had both VPD symptoms and an RTI. Conclusions: The BSABS-VPSES scale provides reliable and valid results in Chinese FUSCH patients. This scale can be used to assess VPD symptom severity in schizophrenics and may contribute to future personalized treatment plans.