Vascular Effects of Myopia in the Eye and Brain A Systematic Literature Review

Abstract

Abstract OBJECTIVES This systematic review investigates the vascular effects of myopia, focusing on changes in ocular and cerebral blood flow. The review addresses two main objectives: understanding how myopia affects the vascular structure and function of the retina and choroid, and exploring potential systemic impacts on cerebral blood flow. This review synthesised existing evidence to understand these vascular alterations and their implications for clinical practice and future research. STUDY DESIGN A systematic search was conducted using databases including PubMed, Web of Science, and MEDLINE, following the PRISMA framework to identify and analyze relevant studies. A total of 41 studies were selected based on predefined inclusion and exclusion criteria. The Joanna Briggs Institute (JBI) Critical Appraisal Tools were employed to evaluate the quality of the included studies. Data extraction followed a standardised approach to ensure consistency and accuracy in capturing relevant findings. RESULTS The findings reveal significant alterations in ocular blood flow, particularly a reduction in retinal vessel density and choroidal thickness in highly myopic eyes. These changes are attributed to axial elongation and mechanical stretching, which disrupt normal vascular function. Such vascular changes may impair blood flow, thereby reducing the supply of oxygen and nutrients to vital ocular tissues. Additionally, evidence suggests potential links between myopia and altered cerebral blood flow, with neuroimaging studies highlighting reduced perfusion and possible neurovascular coupling dysfunctions in highly myopic individuals. CONCLUSION This systematic review highlights the ocular vascular changes associated with myopia along with potential associations with cerebral blood flow alterations. The observed alterations in blood flow and vascular function underscore the importance of early detection and management of myopia to prevent long-term complications. Future research should focus on longitudinal studies and diverse populations to further explore these vascular changes and their implications for clinical practice.