New research, recently published in Photodiagnosis and Photodynamic Therapy, has measured the choroidal circulatory parameters in Han Chinese children aged 4–14 years with mild to moderate myopia. The study explored the relationships between these parameters, age, axial length (AL), and choroidal thickness (ChT) using UWF full-range SS-OCTA.

The 3D choroidal circulatory parameters included choroidal vascular volume (CVV), choroidal stromal volume (CSV), choroidal vascularity index (CVI), and the CVV/CSV ratio, as measured on ultra-wide 24mm x 20mm SS-OCTA imaging of the choroid (fig. 2).

The results showed that both CVV and CSV were negatively correlated with AL and positively correlated with ChT, while no significant correlation was found between age and these parameters. This may be due to developmental increases in CVV and CSV serving as compensatory mechanisms, allowing them to maintain dynamic stability within a certain age range. Interestingly, CVI in children with mild to moderate myopia was unrelated to AL. However, after the age of 8, CVI was positively correlated with age. As both age and AL increase, ChT tends to decrease, and as ChT decreases, CVV and CSV also decrease—though CVV decreases more rapidly than CSV.

These findings suggest that the choroid undergoes changes during the process of myopization. "Choroidal circulation parameters are important biological indicators for monitoring the degree of myopia and predicting its progression."

A 400 kHz full-range swept-source OCTA (BMizar, TowardPi Medical) was used in this study to quantify choroid structure and circulatory status based on an AI-assisted segmentation algorithm for identifying choroidal vessels (fig. 1).

The study was authored by Dr. Haoming Geng and the team of Prof. Junguo Duan from Ineye Hospital of Chengdu University of TCM.

Link to original text: https://www.sciencedirect.com/science/article/pii/S1572100024003120