Choroidal vascular changes in age-related macular degeneration: A protocol for systematic review and meta-analysis

BACKGROUND: As an increasing age-related eye disease, age-related macular degeneration (AMD) is becoming a common cause of irreversible visual loss in elder population. The mechanism of AMD remains uncertain and covers a complex risk factors. Choroidal vascularity index (CVI) is a sensitive parameter obtained by enhanced depth imaging of optical coherence tomography which allows the choroid in more detail and accurate assessment in the pathogenesis of AMD. The objective of this current study is to evaluate choroidal structural alternations measured by CVI in AMD. METHODS: We will review 4 English databases (PubMed, Embase, Cochrane Library, and Web of Science) from their inception until present to select eligible articles. English-language and case–control studies will be accepted. The data extraction content and quantitative analysis will be performed systematically by 2 independent authors. The primary outcome is the alternation of CVI in AMD. The secondary outcomes consist of choroidal thickness (CT), luminal area (LA), stromal area (SA), and total choroidal area (TCA). Subgroup analysis, sensitivity analysis, and publication bias will be performed to check the robustness of the pooled outcome data. RESULTS: Changes of quantitative parameters such as CVI will be obtained in patients with AMD. CONCLUSION: This study will elucidate alternations of choroidal vascular and stromal component in AMD and provide robust evidence on the pathophysiology of AMD. REGISTRATION NUMBER: INPLASY.