A recent study published in Photodiagnosis and Photodynamic Therapy compared the visual and anatomical outcomes of 689 nm laser therapy (689-LT) versus continued subthreshold micropulse laser (SML) therapy in eyes with chronic central serous chorioretinopathy (cCSC) that had shown poor responsiveness to initial SML treatment. The study assessed the choroidal structure and vasculature in both groups using full-range swept-source OCT angiography (SS-OCTA), focusing on choroidal thickness (CT) and the three-dimensional choroidal vascularity index (3D-CVI).

Results demonstrated a significant decrease in choroidal thickness and 3D-CVI in the 689-LT group, confirming the efficacy of switching to 689-LT in cCSC eyes that did not respond well to initial SML therapy. These findings suggest that 689 nm laser therapy could be a promising treatment option for cCSC eyes with persistent subretinal fluid (SRF) following inadequate response to SML treatment.

A high-speed (400 kHz) swept-source OCTA system (BMizar, TowardPi) was utilized in this study to evaluate the choroidal structure and vasculature. The device features a built-in AI-assisted segmentation algorithm, enabling accurate choroidal OCTA imaging. Additionally, its three-dimensional choroidal vascularity index offers a valuable method for quantifying choroidal vascular characteristics.

This research was conducted by Dr. Yue Zhang and the team led by Prof. Xiaobing Yu from Beijing Hospital.

Link to the original study: https://www.sciencedirect.com/science/article/pii/S1572100024004125