Purpose: To evaluate dynamic thiol/disulfide homeostasis in patients with chronic central serous chorioretinopathy (cCSC).Methods: This prospective study included 34 cCSC cases and 37 healthy individuals who were age- and sex-matched. A new colorimetric method for measuring thiol/disulfide homeostasis was used. Native thiol, total thiol/disulfide levels, disulfide/native thiol, disulfide/total thiol, and native thiol/total thiol ratios were measured.Results: The age and gender distributions were similar in both main groups. The mean duration of disease was 47.29 24 months. Native and total thiol levels were significantly lower among the cCSC group relative to the control group (p < 0.001). There was not a statistically significant difference between the cCSC and the control group in terms of disulfide levels (p = 0.492). While disulfide/native thiol and disulfide/total thiol ratios were elevated, the native thiol/total thiol ratio was decreased in the cCSC group (p = 0.017, 0.021, 0.036, respectively). Ratios obtained using plasma native thiol, total thiol, and disulfide levels differed significantly between the both groups.Conclusion: Disulfide/thiol ratio was significantly greater in cCSC patients relative to healthy control subjects. Our results suggest that the oxidative process is involved in the pathogenesis of the cCSC.