Is microvascular abnormality a new endophenotype in schizophrenia?

Background: A new method of assessment of microvascular abnormality in living schizophrenic subjects via retinal imaging was described by Meier et al. (2013). The principal aim of this review is to summarise the relevant knowledge and suggest further avenues of research into this topic.

Subject And Methods: On 20th April 2015, we carried out a search using the computer database system PubMed by using keywords "microvascular AND schizophrenia".

Results: Out of the 17 articles found, only seven were relevant. They are generally consistent with the hypothesis of microvascular pathology and brain inflammation as part of the pathogenesis in schizophrenia. It is important to stress that all studies of brain microvasculature in schizophrenia to date have been post mortem findings, apart from the work by Meier et al. (2013) which is related to retinal imaging in living subjects.

Conclusions: Based on the literature, we suggest the following research and clinical avenues: Firstly, to assess whether microvascular abnormality found via retinal imaging, fulfils the criteria for the schizophrenia endophenotype. Secondly, to examine retinal imaging in high-risk individuals for schizophrenia. Thirdly, to determine whether the fMRI findings and cognitive abilities of schizophrenia patients in both longitudinal as well as cross-sectional studies, is associated with the microvascular abnormalities assessed by the retinal imaging. Fourthly, to determine if there is a correlation between microvascular retinal pathology and the positive or negative schizophrenia symptoms. Furthermore, to determine if childhood maltreatment results in any abnormities in retinal imaging. Lastly, to analyse the genetic background of schizophrenia retinal microvascular pathology and to apply anti-inflammatory agents in the treatment and prevention of schizophrenia if brain vasculitis is confirmed.