Optical coherence tomography biomarkers as predictors of transition to chronic central serous chorioretinopathy after retinal laser photocoagulation

Objectives: To explore the optical coherence tomography (OCT) biomarkers to predict the transition to chronic central serous chorioretinopathy (cCSC) after retinal laser photocoagulation. Methods: Patients enrolled in this study were from a 12-week clinical trial comparing the efficacy and safety of subthreshold micropulse laser (SML) with threshold conventional laser (TCL) for CSC and had extended follow-up for more than 1 year. They were divided into two groups, transited to cCSC group (cCSC group) and did not transited to cCSC group (non-cCSC group) according to fundus examination at the extended follow-up. Collect the best-corrected visual acuity (BCVA) and OCT characteristics of patients at baseline and 12 weeks after laser treatment. Results: Twenty-seven patients were enrolled (42.6 ± 7.7 years old), and duration of follow-up was 178.9 ± 88.8 (57.0–312.0) weeks. Nine patients (33.3%) were assigned to cCSC group, and the other 18 patients (66.7%) were assigned to the non-cCSC group. Twelve weeks after the laser treatment, subretinal fluid (SRF) of 15 patients (83.3%) in non-cCSC group and 5 patients (55.6%) in cCSC group absorbed completely; the height of SRF had statistical difference between two groups ( p = 0.035); rough RPE was less common in cCSC group ( p = 0.030); hyper reflective mass (HRM) was more common in cCSC group ( p = 0.024); more number of hyper reflective foci (HRF) in outer segment of photoreceptor layer were detected in cCSC group ( p = 0.035). From baseline to 12 weeks after laser treatment, the number of HRF in outer segment photoreceptor layer did not change significantly in cCSC group ( p = 0.665) but decreased significantly in non-cCSC group ( p = 0.000). A total of five patients suffered binocular CSC, three of them in the non-cCSC group occurred later than the other two in the cCSC group (129.9–278.3 weeks vs 96.1–114.9 weeks after baseline). Conclusion: SRF, rough RPE, HRM, and number of HRF in outer segment photoreceptor layer 12 weeks after laser treatment, and change in the number of HRF in outer segment photoreceptor layer from baseline to 12 weeks after laser treatment may predict the transition to cCSC.