Investigating the Hypothesis of Stress System Dysregulation as a Risk Factor for Central Serous Chorioretinopathy: A Literature Mini-Review

Background: This mini-review addressed the question "what do we know about the association between the dysregulation of stress systems (HPA axis and SAM) and the onset and prognosis of CSC in adult populations?" Methods: The literature mini-review was conducted through electronic searches using the PubMed, Web of Science, and Scopus databases. All published human and animal studies with both observational and experimental designs from 1966 to October 2018 were included. Results: Our search identified 229 reports, of which 32 articles were ultimately identified to be reviewed in this paper. Among these key articles, twenty-three were related to exogenous and/or endogenous high glucocorticoids as risk factors for CSC, seven were related to Type-A behavior and chronic psychological distress as risk factors for idiopathic CSC, and two were related to stress-induced animal models of CSC. Nineteen out of twenty-three studies in the first group reported a consistent association between high circulating corticosteroids and the onset and prognosis of CSC. Six out of seven studies in the second group reported a consistent association between stress-induced allostatic (over)load and the appearance of more- or less-severe CSC disorders, assuming that elevated circulating steroids may constitute a kind of risk factor for the eye through dysregulation of the HPA axis. All the selected studies reported HPA axis dysregulation as a possible common factor to explain the association between high circulating corticosteroids and CSC. In contrast, the involvement of the SAM system is only indirectly taken into consideration through the PA and HR measures and/or plasma and 24-h urinary catecholamine levels. Therefore, information regarding the involvement of SAM system dysregulation in the onset and prognosis of CSC is lacking. This observation is particularly relevant in view of the fact that animal models of CSC in monkeys are primarily induced by adrenergic hypertonia and that the course of experimental CSC is not further exacerbated by the administration of corticosteroids.