Pathogenesis of myopic choroidal neovascularization: A systematic review and meta-analysis.

Myopic choroidal neovascularization (CNV) is a vision-threatening complication of high myopia. Here we systematically review cohort, case-control, and cross-sectional studies in PubMed, Embase, and Web of Science; and summarize the associated factors of myopic CNV using meta-analysis where applicable. Among 1,333 records assessed, 50 were found eligible, all having a low to moderate risk of bias. Highly myopic eyes with CNV had a higher risk of lacquer cracks (OR=2.88) and of patchy chorioretinal atrophy (OR=3.43) than those without. The mean posterior staphyloma height (um) was greater in myopic CNV eyes than in highly myopic eyes without CNV (MD=82.03). The thinning of choroidal thickness (um) between myopic eyes with and without CNV differed significantly (MD=-47.76). The level of vascular endothelial growth factor (VEGF, pg/ml) in the aqueous humor of myopic CNV eyes was significantly higher than highly myopic eyes without CNV (MD=24.98), the same as IL-8 (pg/ml, MD=7.73). Single-nucleotide polymorphisms in the VEGF, CFI, and COL8A1 genes were associated with myopic CNV. We found that myopic CNV eyes have a higher ratio of lacquer cracks and patchy chorioretinal atrophy, thinner choroid, greater posterior staphyloma height, and a higher level of VEGF and IL-8 in aqueous. Structural predisposing lesions, hemodynamic, genetic, and systemic factors are also associated with myopic CNV.