Background: Retina is considered as a window to the brain due to the similarities in terms of development and pathologies. Optical coherence tomography (OCT) can perform quantitative examinations in the retina. In this study, we aimed to investigate the effects of drugs used in schizophrenia and bipolar disorder (BD) on retinal nerve fiber layer (RNFL) and macular thickness.
Subjects and methods: The study included schizophrenia (n=35) and euthymic BD (n=46) patients on various medications, and age, gender matched healthy control group (n=31). For retinal evaluation, measurements of RNFL and macula were performed with Optovue RTVue Premier OCT.
Results: In the schizophrenia group, chlorpromazine equivalent dose of antipsychotics was a statistically significant negative predictor of left RNFL nasal superior region thickness. In the BD group, serum valproate level was a significant positive predictor of thickness in the right macular inferior outer, left macular nasal outer region, right RNFL inferotemporal, left temporal and inferotemporal regions.
Conclusion: Since the retina consists of neurons, morphological or functional examination of retina may be beneficial for the evaluation of the effects of psychopharmalogical treatments in schizophrenia and BD. The outcome of this study implies that valproate has neuroprotective effects on the optic nerve and macula, and this finding is consistent with the literature implying neurotrophic effects of valproate.