A retrospective cross-sectional study analyzed 1420 patients (2610 eyes) with high myopia examined between 2015 and 2024 at Lanzhou Aier Eye Hospital. Chorioretinal damage was documented in 40.0% of eyes, with the most common lesions being diffuse atrophy (16.1%), foveoschisis (11.9%), and area atrophy (8.2%). Older age, greater axial length of the eye, more negative spherical equivalent, and thinner choroid were independently associated with the presence of pathology. Chorioretinal changes were graded using the ATN classification and the model demonstrated stable calibration with high discrimination. The predicted estimates indicated a significant burden especially in eyes with an axial length ≥ 32 mm. The findings highlight the need for targeted early surveillance based on biometric parameters.