Abstract
Schizophrenia is a neuropsychiatric disorder in which visual processing abnormalities are common. An unanswered question in this field is the extent to which some of these functional impairments (e.g., contrast sensitivity) may be due to altered retinal structure and function. This question has gained in importance with two recent studies showing retinal nerve fiber layer (RNFL) thinning in schizophrenia, as revealed by spectral domain optical coherence tomography (SD-OCT). OCT is a noncontact imaging technology that can image retinal structure (including thickness) in vivo with a resolution of 10 microns or less using optical backscattering of light. It has been used to document RNFL thinning in neuropsychiatric disorders such as multiple sclerosis and Parkinson’s disease. A second unanswered question in the schizophrenia literature is whether retinal abnormalities can serve as markers of global brain function. Because the retina and optic nerve are outgrowths of brain tissue, they are considered part of the central nervous system, and some past OCT studies in other neuropsychiatric disorders (e.g., multiple sclerosis, Parkinson’s disease) indicate that retinal tissue loss parallels cortical degeneration and cognitive decline. This has not yet been investigated in schizophrenia, however, although progressive gray and white matter loss, and cognitive decline, have been repeatedly documented, especially early in the illness. To make progress on the above questions, we are generating SD-OCT data on RNFL and macular thickness, and determining relationships with visual acuity, contrast sensitivity, perceptual organization, and global cognitive capacity (expected sample sizes of 20 patients and controls each before VSS 2015). To date, 6 of 7 schizophrenia patients have demonstrated significant RNFL and/or macular thinning compared to control norms. Moreover, extent of thinning is significantly related to illness chronicity, controlling for age, and to poorer visual acuity. Relationships between OCT findings and visual and cognitive task performance will be reported.
Meeting abstract presented at VSS 2015