Posterior staphyloma and long-term structural and visual trajectories in high myopia

Purpose: To determine whether posterior staphyloma (PS) is associated with long-term trajectories of ocular structural changes, myopia-related complications and visual outcomes in high myopia. Methods: This prospective longitudinal cohort study included 614 highly myopic eyes from the Zhongshan High Myopia Cohort Study, followed for up to 12 years. Eyes were categorised by PS status: baseline PS (n=46), new-onset PS (n=94) or no PS (n=474). The associations between PS and myopic macular degeneration (MMD) progression, myopic traction maculopathy (MTM) and plus lesions incidence, longitudinal changes in ocular parameters and incident moderate-to-severe visual impairment (MSVI) were assessed. Results: PS was independently associated with increased risks of MMD progression (OR 3.39, 95% CI 1.81 to 6.35, p<0.001), MTM (OR 2.25, 95% CI 1.06 to 4.77, p=0.034) and incident plus lesions (OR 3.15, 95% CI 1.16 to 8.57, p=0.024). The highest risks of MTM and plus lesions were observed in eyes with new-onset PS. Eyes with PS demonstrated significantly faster axial elongation (mean annual rate: baseline PS, 0.120 mm (95% CI 0.099 to 0.142); new-onset PS: 0.129 mm (95% CI 0.114 to 0.145); no PS: 0.066 mm (95% CI 0.060 to 0.073), p<0.001) and a fivefold higher risk of MSVI (95% CI 1.36 to 18.45, p=0.016). Conclusions: PS marks a pivotal structural transition in high myopia, identifying a phase of accelerated axial elongation, increased risk of complications and worse visual outcomes, and may serve as a key marker for risk stratification and an important target for early intervention.