A meta-analysis, published in Schizophrenia Research: Cognition, suggests that retinal changes may precede the behavioral onset of schizophrenia. 

Researchers from Rutgers University and Mount Sinai’s New York Eye and Ear Infirmary reviewed the current evidence on visual disturbances in schizophrenia and concluded that if further research links certain retinal changes to the progression of schizophrenia, doctors could better diagnose and manage schizophrenia in high-risk patients who have not yet presented with the behavioral component of the disease. For example, reduced b-wave amplitude in electroretinography (ERG) readings were found in high-risk pediatric patients who did not display behavioral symptoms of schizophrenia.

For patients who are already being treated for the disease, the state of the retina would be an indicator of the need for additional or new medications to prevent the onset of psychotic episodes. Differences have been noted in A-wave flash ERG readings before and after hospitalizations for acute bouts of psychosis; reduction in A-wave amplitude existed before hospitalization and treatment for a psychotic episode, but not after. 

“Measurement of retinal changes may help doctors, in the future, adjust schizophrenia treatment for each patient,” study co-author Richard B. Rosen, MD, says in a press release. 

Another important retinal feature noted in the meta-study was retinal nerve fiber layer (RNFL) thinning, which may have diagnostic implications for ODs.

“Some, but not all, studies indicate thinning of the retinal nerve fiber layer in schizophrenia. Evidence from other neuropsychiatric populations suggests that thinning parallels loss of brain volume, cognitive decline and illness progression in these conditions,” says Steven Silverstein, PhD, the study’s first author. “It is not yet known the extent to which retinal nerve fiber layer thinning in schizophrenia parallels any such changes; however, if it is later found that RNFL thinning does predict these changes, this would have several implications,” Dr. Silverstein says. 

First, he recommends an OCT exam. Second, if the exam indicates RNFL thinning, order a more expensive and time-consuming structural brain scan, as well as neuropsychological testing and functional assessment.

“If these tests indicate brain volume loss, cognitive decline or both, this would suggest a need for cognition-enhancing medication and for cognitive remediation, which has been shown to improve cognition and slow progressive grey matter loss in younger schizophrenia patients,” Dr. Silverstein says.

Silverstein SM, Rosen R. Schizophrenia and the eye. Schizophrenia Research: Cognition. 2015 June;2(2):46-55.