Choroidal changes and association with Gaussian curvature in high myopic eyes with posterior staphyloma in ultra-wide-field optical coherence tomography angiography.

Purpose: To evaluate choroidal changes in high myopic (HM) patients with posterior staphyloma (PS) and explore their association with Gaussian curvature (K) using ultra-wide-field optical coherence tomography angiography (UWF-OCTA).

Methods: HM patients with wide macular PS (Type I PS) and without any PS (control) were recruited. Highest K values (K_max) and choroidal parameters-vessel flow density (VFD), choroidal vascularity volume (CVV) and index (CVI), thickness, and volume-were compared in central and peripheral regions, and the fovea-centered 12-mm ETDRS quadrants of 24 × 20 mm UWF-OCTA images. Associations between choroidal parameters and K values in Type I PS eyes were analysed using multiple linear regression analysis, controlling for the confounding effect of AL.

Results: Type I PS eyes showed increased K_max in various subregions (p < 0.05), except the 12-mm ETDRS superior quadrant. CVV, choroidal thickness, and volume were higher in the peripheral region of the UWF-SS-OCTA image in Type I PS eyes (p < 0.05). Central CVI and large and medium choroidal vascular layer-VFD were significantly lower in Type I PS eyes (p < 0.05). Correlation analysis revealed a negative association between macular K_max and central CVI (p < 0.05). In the peripheral region, K_max showed a positive correlation with choroidal thickness and volume (p < 0.05). These correlations were partially confirmed across several quadrants of the 12-mm ETDRS grid.

Conclusion: Type I PS eyes exhibit attenuated choroidal perfusion and a potentially reorganized choroidal structure and circulation, associated with Gaussian curvature severity. UWF-OCTA shows promise for non-invasive visualization of the choroidal alterations in PS.