Choroidal volume decrease associated with stromal regression in adult myopia: A high-resolution optical coherence tomography angiography study

This is the authors' abstract. We don't add key points for this paper.

• AI algorithms assist in quantifying three-dimensional choroidal changes in myopic eyes using SD-OCT data. • Choroidal thickness, vascularity, and stroma volume decrease as myopia severity increases. • The mean choroidal thickness and axial length are independent factors influencing the progression of high myopia [R2-C2]. • Increased choroidal vascular index (CVI) correlates with higher degrees of myopia. • The reduction in stromal volume may provide insights into myopia prevention and management. Observing choroidal volume changes in myopia with various degrees via swept-domain optical coherence tomography (SD-OCT) images. 215 eyes of 118 myopia patients were divided into 3 groups according to spherical equivalent: low myopia (LM), moderate myopia (MM) and high myopia (HM). Choroidal thickness (CT), choroidal volume (CV), vascular volume (VV), stromal volume (SV), choroidal vascular index (CVI), and mean choroidal vascular diameter (CVD) in the Haller and Sattler layers were measured. Choroidal capillary (CC) blood flow deficit percentage (FD%) was measured using Sauvola local threshold method through Enface images. As myopia degree increased, CT, CV and SV decreased, while CVI increased, CVD remained unchanged, and VV decreased significantly in the nasal and superior regions. Foveal CC FD% of HM was higher than that of LM and MM (P <0.05). The CCFD% of HM in the superior and total macular area also increased compared with MM (P <0.05). SE was positively correlated with CT, CV, and SV, while negatively correlated with CVI. CT was significantly correlated with SV and VV. And, the mean CT (P <0.05) and axial length (P <0.001) were the independent protection and risk factors for HM. ROC curve area was 0.800, with cutoff values of 75.11 Px for CT and 26.24 mm for axial length. With myopia progression, the average choroidal thickness and volume decreased, primarily due to reduced stromal volume.