Electroretinographic anomalies in schizophrenia.

Flash electroretinography (fERG) has been used to identify anomalies in retinal cell function in schizophrenia. Several consistent findings have now emerged, but several potentially important parameters have not yet been investigated. In this study, we recorded light- (photopic) and dark-adapted (scotopic) fERG data from 25 schizophrenia patients and 25 healthy control subjects to (1) determine if past key findings on abnormal photoreceptor and bipolar cell signaling could be replicated; (2) for the first time, examine retinal ganglion cell functioning using the photopic negative response of the fERG; (3) also for the first time, determine responsiveness of schizophrenia patients to a flickering stimulus, as an additional method to isolate cone photoreceptor function; and (4) determine if schizophrenia-related changes in the fERG could be detected using a portable hand-held ERG device. In both photopic and scotopic conditions, schizophrenia patients demonstrated weakened photoreceptor and bipolar cell activations that were most pronounced in response to the most intense stimuli. A reduced cone response to a flicker stimulus and attenuation in ganglion cell activity were also observed in the schizophrenia group. In general, groups did not differ in implicit time of retinal cell responses. These findings (1) replicate and extend prior studies demonstrating reduced photoreceptor (both rod and cone) and bipolar cell functioning in schizophrenia; (2) indicate that retinal ganglion function abnormality can also be detected using fERG; and (3) indicate that these anomalies can be detected using a portable testing device, thereby opening up possibilities for more routine administration of ERG testing. (PsycINFO Database Record (c) 2018 APA, all rights reserved).