Efficacy of fluorescein angiography guided 532 nm continuous-wave green laser used as a non-damaging subthreshold laser in the treatment of central serous chorioretinopathy.

PURPOSE: To evaluate the anatomical and functional outcomes of fluorescein angiography (FA)-guided focal subthreshold 532-nm continuous-wave green laser in patients with simple versus complex central serous chorioretinopathy (CSC). METHODS: This retrospective, single-center study included 50 eyes of 50 patients with persistent CSC lasting ≥ 6 months. Patients were classified as simple or complex CSC based on multimodal imaging. All patients underwent FA-guided focal subthreshold laser, with energy titrated to avoid visible burns. Outcome measures included changes in best-corrected visual acuity (BCVA, logMAR), subretinal fluid (SRF) height, and subfoveal choroidal thickness (SFCT). Statistical comparisons were performed using paired and independent tests, with p < 0.05 considered significant. RESULTS: Of the included eyes, 29 (58%) were classified as simple CSC and 21 (42%) as complex CSC. Baseline age and sex distribution were comparable between groups (p > 0.01). At 3 months, SRF height significantly decreased in both groups (simple: 127.4 ± 38.6 μm to 35.2 ± 19.7 μm, p < 0.001; complex: 118.7 ± 36.1 μm to 65.3 ± 28.4 μm, p < 0.001), with a greater reduction in the simple group (p < 0.001 between groups). Complete SRF resolution was achieved in 23 eyes (79%) of the simple group versus 2 eyes (9.5%) of the complex group (p < 0.001). SFCT decreased significantly in both groups, with a more pronounced change in simple CSC (simple: - 36.9 μm, p < 0.001; complex: - 15.9 μm, p > 0.001; p < 0.001 between groups). BCVA improved significantly in the simple group (0.35 ± 0.12 to 0.20 ± 0.10 logMAR, p < 0.01) but not in the complex group (0.40 ± 0.15 to 0.38 ± 0.16 logMAR, p > 0.001). CONCLUSIONS: FA-guided focal subthreshold 532-nm laser provided robust anatomical and functional benefits in simple persistent CSC, with a high rate of complete SRF resolution and visual improvement, while complex CSC showed limited response. By targeting only angiographically active leakage sites, this approach minimized the number and area of laser applications, potentially reducing collateral tissue damage. CLINICAL TRIAL REGISTRATION: This study was a retrospective observational analysis based on clinical data of patients who had previously undergone fluorescein angiographyguided subthreshold laser treatment. Therefore, it does not meet the criteria of a prospective interventional clinical trial, and registration in a clinical trial registry was not applicable.