Association between amblyopia and benign paroxysmal positional vertigo: nationwide cohort study.

Amblyopia is a developmental disorder of the central nervous system resulting in visual impairment, with potential impacts on cognitive and motor functions. This study evaluated the risk of benign paroxysmal positional vertigo (BPPV) in patients with amblyopia over a 9-year follow-up. Data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) was used. Amblyopia (n = 2,660) and non-amblyopia (n = 2,660) groups were matched by Propensity Score. The primary endpoint was the diagnosis of BPPV. Amblyopia was associated with a higher BPPV risk (HR 2.25, 95% CI: 1.49-3.41). The risk was lower in men (HR 0.47, 95% CI: 0.31-0.73) but increased with age (20-39 years: HR 3.35 [95% CI: 1.93-5.83]; 40-59 years: HR 9.92 [95% CI: 6.05-16.28]; ≥60 years: HR 14.80 [95% CI: 7.65-28.69]). In this long-term study, individuals with amblyopia had a 2.25-fold increased risk of developing BPPV compared to controls. These findings suggest that visual and vestibular functions are more closely linked than previously recognized, indicating that sensory disorders such as amblyopia may have broader neurological implications beyond vision alone. Nevertheless, the findings should be interpreted with caution and considered exploratory, providing population-level evidence for potential visual-vestibular associations that require validation in future prospective studies.