Introduction: Central serous chorioretinopathy (CSC) is a chorioretinal disease that usually affects younger, working population. If a remission occurs spontaneously within the first 3 months after the episode onset, visual acuity usually returns to the pre-episode level. In patients with a persistent CSC episode, irreversible vision function loss occurs. These patients need treatment. One of the treatment options is subthreshold micropulse laser (MPL), which is, similar to other treatment options, only partially effective.
Purpose: The purpose of our study was to observe morphological and functional parameters after spontaneous CSC resolution and after the treatment with MPL. Moreover, we wanted to identify biomarkers that could be associated with spontaneous CSC remission and MPL treatment effectiveness and to investigate associations between functional and morphological parameters during and after a CSC episode.
Methods: In our study, we have included 50 patients with an acute CSC episode. At presentation, following multimodal imaging was performed: optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), fluorescein angiography (FA), indocyanine green angiography (ICGA), and autofluorescence (FAF); and following visual function tests were done: best corrected visual acuity (BCVA), contrast sensitivity (CS), microperimetry (MP), multifocal electroretinography (mfERG). In all patients, all multimodal imaging and visual function tests were repeated at 3 and 6 months, except FA and ICGA. Patients with a persistent CSC episode at 3 months were treated with MPL. Patients with a spontaneous remission at 3 months were observed only. Biomarkers for spontaneous resolution were observed at presentation, biomarkers for MPL treatment effectiveness just before the treatment (3 months after the CSC episode onset).
Results and conclusions: In 19 patients, who were grouped to the spontaneous remission group (sCSC), subretinal fluid (SRF) resolved spontaneously within the first 3 months. In the remaining 31 patients, who were grouped to the persistent CSC group (pCSC), SRF fluid persisted 3 months after the episode onset. In both groups, SRF resorption resulted in reduced average central retinal thickness (CRT) and macular volume (MV). Moreover, average choroidal thickness (CT), pigment epithelium detachment (PED) width and height decreased in both groups, however, number of hyperreflective foci (HF) changed variably. Patients in the pCSC group were on average older, female, and had wider PED, increased number of HF, thinner choroid and diffuse RPE alterations at presentation (as a pair). In 15 out of 31 patients, MPL treatment resulted in a remission. Patients with a good response to the MPL treatment (dCSC) had on average lower SRF and narrower PED. In the sCSC group, functional vision parameters mostly improved at SRF resolution (at 3 months), and have not changed significantly thereafter, except CS, which improved more gradually and continued to improve until 6 months. In the pCSC group, the visual function parameters had been improving more slowly and gradually due to the prolonged course of SRF reabsorption. The sCSC group had in comparison with the pCSC group at 6 months higher average amplitude densities in the central mfERG ring (mfERG-A1). Differences in the more peripheral rings (mfERG-A2 to A5) were not statistically significant. Patients, who were treated with MPL and achieved post episode BCVA 6/6, had retinal sensitivity and amplitude densities on the lower side of 95% confidence intervals. Visual function parameter deficits were mostly confined to the topographical area of the SRF accumulation.
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