Retinal and Choroidal Microvasculature at Different Myopia Severities: A Systematic Review and Meta-Analysis

This study systematically evaluates changes in retinal and choroidal microvasculature with increasing myopia severity.

Conflicting results in reported studies on the changes in retinal and choroidal microvasculature with increasing myopia severity require comprehensive analysis to guide patient management.

The PubMed, Embase, and Web of Science databases were thoroughly searched for studies published before May 8, 2025 on retinal or choroidal changes across different myopia severities. Included were studies with cross-sectional or prospective case-control and cohort designs that reported outcomes of foveal avascular zone (FAZ) area and vessel densities (VD) in the retina and choroid. The risk of bias was assessed by the Newcastle-Ottawa Scale and the Agency for Healthcare Research and Quality tools. Funnel plot with Egger test assessed potential publication bias. Meta-regressions were conducted to identify potential moderators in subgroup meta-analyses with high heterogeneity. The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO): CRD42023402550.

A total of 47 studies comprising 7293 eyes were included. Highly myopic eyes demonstrated significantly enlarged FAZ area in both the superficial capillary plexus (SCP) (P = 0.049, standard mean difference [SMD]: 0.37, 95% confidence interval [CI]: [0.00, 0.74], I² = 82%) and deep capillary plexus (DCP) (P = 0.001, SMD: 0.61, 95% CI: [0.24, 0.98], I² = 83%). Macular VD was significantly reduced in the SCP for moderate and high myopia (HM) subgroups (P = 0.003 and P < 0.001, respectively) and in the DCP for the HM subgroup (P < 0.001). Significant VD reductions were also observed in parafoveal (SCP: P < 0.001, DCP: P = 0.012) and perifoveal (SCP: P = 0.006; DCP: P < 0.001) regions in the HM subgroup in both plexuses. Peripapillary VD showed consistent reductions across mild, moderate, and HM subgroups (all P ≤ 0.033). No significant differences were observed in choriocapillaris VD or flow area.

This meta-analysis revealed significantly enlarged FAZ areas and reduced VD in the macular and peripapillary regions with increasing myopia, especially in HM. These findings enhance the understanding of myopia-related fundus microvascular changes, guiding the clinical management and screening of patients with HM.