LAUSR

Dear Editor, Central serous chorioretinopathy (CSC) is a common retinal disorder characterized by serous retinal detachment (SRD) in the macular region. Recent studies using enhanced depth imaging optical coherence tomography (EDI-OCT) have revealed that central choroidal thickness (CCT) was significantly larger in eyes with CSC than in normal eyes [1], and the thickness gradually decreased as the CSC regressed [2, 3]. In addition, indocyanine green angiography (ICGA) findings show a staining of the inner choroid, which indicates choroidal vascular hyperpermeability [4]. Therefore, accumulating evidence proclaims the increased hydrostatic pressure and/or dysregulation of choroidal circulation to be the primary events in CSC, which lead to alteration in the integrity of the RPE and focal leakage beneath an overlying neurosensory retina, i.e., microrip and SRD respectively. Previously, using laser speckle flowgraphy (LSFG), we quantitatively assessed the time course of choroidal circulation in the resolution phase of acute CSC and reported that choroidal blood flow velocity significantly decreased in the macular region [5]. However, the relevance between choroidal circulation and structural changes during the recovery period of CSC has not been analyzed so far. The purpose of this study was to investigate the relationship between circulation hemodynamics and morphology of the choroid in patients with acute CSC. In this observational case series, 27 eyes of 27 patients (18 males and nine females; average age, 57.3 ± 11.3 years) with acute CSC were included. LSFG and EDI-OCT were performed at baseline, 3, and 6 months later. The average values of the mean blur rate (MBR) at the macula and the CCT were compared at each stage, as described elsewhere [6]. The current study was approved by the ethics committee of Hokkaido University Hospital and followed the tenets of the Declaration of Helsinki. In all cases, subretinal fluid (SRF) was absorbed (Fig. 1) and mean duration from the first visit to SRF absorption was 4.5 ± 2.1 months. The CCT measured by EDI-OCT was 361 ± 120 μm at the initial visit and decreased to 337 ± 110 μm and 319 ± 109 μm at 3 and 6 months after the first measurement respectively (Fig. 2a). There were statistically significant decreases in the CCT values at 3 and 6 months against the baseline value (pairwise comparisons, Phock = 0.0043 and Phock < 0.0001). In addition, MBR, a quantitative index of relative blood flow velocity [7], was measured at the macula using LSFG-NAVI (Softcare, Fukuoka, Japan) and LSFG Analyzer software (v 3.0.47; Softcare), as described elsewhere [5], at 3 and 6 months. The average macular MBR against baseline (100%) decreased to 90.9 ± 8.7% and 84.6 ± 9.8% at 3 and 6 months after the first measurement respectively (Fig. 2b). There were also statistically significant decreases at 3 and 6 months against the baseline value * Kousuke Noda [email protected]