Anterior Suprachoroidal Fluid Following Photodynamic Therapy for Chronic CSC: An Anterior-Segment Optical Coherence Tomography Study

The early anterior uveal response after photodynamic therapy (PDT) in chronic central serous chorioretinopathy (CSC) has not been systematically characterized. This study aimed to determine the incidence of anterior supraciliary/suprachoroidal fluid (SCF) detected by anterior-segment optical coherence tomography (AS-OCT) after half-fluence PDT and to examine its association with macular and choroidal structural changes. In this retrospective single-center case series, 29 eyes of 29 patients with chronic CSC treated with half-fluence PDT were analyzed. AS-OCT and macular OCT were obtained at baseline and day 3, and 1 month. Eyes were classified as SCF-change (new or increased SCF at day 3) or SCF-stable. The primary outcome was the incidence of SCF at day 3. Secondary outcomes included best-corrected visual acuity (BCVA), central macular thickness (CMT), central choroidal thickness (CCT), and the incidence of PDT-induced acute exudative maculopathy (PAEM). Continuous variables are presented as median interquartile range, and nonparametric statistical tests were used. SCF was detected in 4/29 eyes (13.8%) at baseline and in 14/29 eyes (48.3%) at day 3. Eleven eyes (37.9%) were classified as SCF-change and 18 (62.1%) as SCF-stable. In the SCF-change group, CMT increased significantly from 366.0 237.0, 405.0 μm at baseline to 490.0 263.0, 691.5 μm at day 3 (p = 0.002). In contrast, the SCF-stable group showed no significant change. The magnitude of CMT increase was significantly greater in the SCF-change group (p = 0.003). PAEM occurred more frequently in the SCF-change group than in the SCF-stable group (7/11 vs. 2/18; Fisher’s exact test, p = 0.010; odds ratio 14.0, 95% confidence interval 2.06–95.09). Anterior SCF frequently appeared in the early phase after PDT for chronic CSC and was associated with greater short-term increases in macular thickness and a higher incidence of PAEM. Detection of anterior SCF by AS-OCT may provide a useful early imaging marker reflecting acute choroidal reactivity following PDT.