Quantitative choroidal evaluation after subthreshold micropulse laser in chronic central serous chorioretinopathy using ultrawide-field SS-OCTA

To assess the choroid and choriocapillaris after subthreshold micropulse laser (SML) at 577 nm in chronic central serous chorioretinopathy (CSC) via ultrawide field swept-source optical coherence tomography angiography (UWF SS-OCTA) and to explore the resolution rate of SRF varied among different types of vortex vein dilatation pattern (VVDP). The study involved the evaluation of 44 eyes from 39 patients with a diagnosis of CSC. All eyes affected by CSC received SML treatment. To compare best-corrected visual acuity (BCVA) at baseline and at one and three months posttreatment, the height and area of subretinal fluid (SRF), as well as the choroidal parameters in nine subfields of wide-angle fundus images, were measured: choroidal thickness (CT), three-dimensional choroidal vascularity index (3D-CVI), mean choroidal vessel volume per unit area (mCVV/a), mean choroidal stroma volume per unit area (mCSV/a), and choriocapillaris vascular density (CCVD). The vortex vein drainage pattern (VVDP) was classified as superior dominant, symmetric, or inferior dominant based on ultrawide-field OCTA images. Forty-four CSC eyes from 39 patients (5 females, 34 males) were included in our study, with a mean age of 43.9 ± 8.44 years. There were no significant improvements in BCVA or CCVD at one-month and three-month follow-ups ( P > 0.05). However, a significant reduction was observed in the SRF and average values of CT, 3D-CVI, mCVV/a and mCSV/a, compared with the baseline values ( p < 0.05 in all analyses). CT findings in the superonasal, central, inferotemporal, and lower regions were significantly lower than those at baseline ( P < 0.05). The 3D-CVI in the upper, superonasal, temporal, central, nasal, and lower regions was significantly lower than that at baseline ( P < 0.05). Compared with those at baseline, mCVV/a in the upper, superonasal, central, nasal, inferotemporal, and lower regions significantly decreased ( P < 0.05). Compared with that at baseline, the mCSV/a in all regions significantly decreased ( P < 0.05). The SRF resolution rate varied among different VVDP types, with the inferior dominant type showing the highest rates and the superior dominant type showing the lowest rates. A subthreshold micropulse laser (577 nm) was associated with progressive resolution of subretinal fluid over the 3-month follow-up period, accompanied by sector-specific reductions in choroidal thickness (CT), 3D choroidal vascular index (3D-CVI), microvascular volume per area (mCVV/a), and mean choroidal stroma volume per unit area (mCSV/a).