Retinal neural and microvascular findings in psychotic disorders and high-risk states

While nearly all retinal imaging studies in schizophrenia indicate impairments, the association with diagnosis is not strong. This is likely due to differences in the extent of retinal thinning in earlier vs later stages of illness, and on retinal neurodegeneration being most pronounced in only one or more subtypes of patient. In this presentation, I will review findings from studies using optical coherence tomography (OCT) and OCT angiography (OCTA) that demonstrate an accelerated aging pattern of retinal neural layer thinning, and earlier reductions in retinal microvasculature density in schizophrenia. These data also indicate that the findings in schizophrenia are more pronounced than in patients with mood disorders, and that they correlate significantly with the polygenic risk score for schizophrenia and with genes that code for the neuroinflammatory response. Data from our clinical high risk for psychosis population are, overall, within the normal range, but increased positive symptoms are related to lower microvasculature density values and greater neural layer thickness, suggesting a neuroinflammatory response. Overall, the data suggest that retinal neural layer thinning is progressive in schizophrenia, although the rate and duration of progression varies, and that thinning of the microvasculature occurs earlier than neurodegeneration. Because the retina can be considered a window to the brain, these findings suggest biomarker possibilities for patient monitoring.