The Urinary 6-Sulfatoxymelatonin Level in Patients with Central Serous Chorioretinopathy and Its Correlation with Choroidal Vasculature

Abstract Purpose: To investigate the changes in melatonin secretion levels and its association with choroidal vasculature in patients with central serous chorioretinopathy (CSC) . Methods: In this study, we enrolled 30 male patients diagnosed with CSC and 30 healthy male controls. We assessed the choroidal vasculature system of all participants using ultra-widefield swept-source optical coherence tomography angiography (UWF-SS-OCTA). Specifically, we measured choroidal vascular volume (CVV), choroidal vascularity index (CVI), and choroidal thickness (CT). Additionally, we determined the levels of urinary 6-sulfatoxymelatonin in participants using enzyme-linked immunosorbent assay. Finally, we evaluated the correlations between 6-sulfatoxymelatonin/creatinine (6-SMT) ratios and choroidal vascular parameters in CSC patients. Results: The levels of urinary 6-SMT in CSC patients (24.8, 20.2 − 28.1 ng/mg) are significantly lower than the control group (36.1, 30.0 − 45.2 ng/mg, P < 0.001). Compared with the control group, CSC patients exhibited significantly larger average CVV, CVI, and CT (CVV: 44.6 ± 8.9 vs. 38.2 ± 9.4 mm³, P < 0.01; CVI: 34.7 ± 1.8 vs. 33.3 ± 3.0%, P = 0.03; CT: 242.3 ± 48.0 vs. 207.2 ± 48.3 μm, P = 0.01). In all regions, negative correlations were found between 6-SMT and CVV (maximum r-value was -0.53, P < 0.01), CVI (maximum r-value was -0.56, P < 0.01), and CT (maximum r-value was -0.54, P < 0.01) in CSC patients. The linear regression analysis showed that 6-SMT was the only predictor of CVV, CVI, and CT (P < 0.05). Conclusion: This study suggests that the decrease in melatonin secretion levels may partially contribute to the pathological progression of the choroid in CSC. This study provides valuable insights for the development of future treatment methods for CSC.