Analysis And Comparison Of Features On OCT In Patients With Central Serous Chorioretinopathy And The Location Of Leakage Point On OCT

Purpose:The imaging features of acute and chronic central serous chorioretinopathy(CSC)were analyzed by fundus fluorescein angiography(FFA)and spectral-domain optical coherence tomography(SD-OCT)scanning to provide a basis for its diagnosis,differential diagnosis and treatment.By analyzing the OCT imaging characteristics corresponding to the leakage point,the preliminary localization method for the acute CSC leakage points in order to provide a method for localizing the leakage point in patients who could not undergo FFA examination.Methods:62 eyes of CSC patients with initial onset were excluded by fundus photography,OCT densification scanning and FFA examination.FFA manifestations of CSC patients and morphological changes of retinal layers on OCT were observed,and imaging characteristics and corresponding clinical significance or mechanism of CSC were analyzed;The FFA images and OCT images of patients with acute CSC were superimposed by Adobe Photoshop software to observe the corresponding OCT imaging characteristics of the leakage point.Results:In patients with acute CSC,OCT imaging features include typical serous retinal detachment(SRD),PED/RPE protuberance,RPE microrip,varying numbers of hyperreflective spots in the outer retina,smooth,thickened,or granular appearance of the photoreceptor outer segment(PROS)with progression of the disease as well as hyperreflective fibrin exudation and subsidence of the outer neuroretinal layer under SRD;and there is a new finding that hyperreflective bands are seen in the outer nuclear layer of SRD located in the macular area.The main findings on FFA were clear leakage points and delineation of neuroepithelial detachment areas in the late stage.The imaging features of chronic CSC are more complex and variable compared to acute CSC.OCT imaging features include a wide range of SRD not limited to the macular area.RPE damage may show RPE protuberance,microrip,defects,atrophy or proliferation and other changes.More punctate hyperreflective material is observed in the outer retinal layer with granular appearance of the PROS layer and dense fibrin exudation under SRD.Hyperreflective spots are observed in the choroid and choroidal vascular walls show hyperreflexive changes.And hyperreflective bands are also observed in the outer nuclear layer of SRD,a newly discovered imaging feature.A small number of patients may develop complications such as macular edema,retinal folds,and epiretinal membranes due to long-term damage to the retina.There was no clear leakage point in FFA in chronic CSC,the RPE damage mainly manifested as RPE microleakage or RPE staining,and those with RPE atrophy presented transparent fluorescence.The area of RPE injury due to downward movement of SRD effusion with gravity was outlined in the late stage.Those with RPE proliferation showed blocked fluorescence.OCT features corresponding to the leakage point were analyzed by OCT encrypted scanning of the lesion area in patients with acute CSC as follows: Superimposition analysis on Adobe Photoshop software by FFA pictures and OCT pictures showed that40(70.18%)of 57 RPE changes(RPE protuberance/ PED)in the detachment area corresponded to the leakage point,while 35(87.50%)of the pros thinned above the 40 RPE changes,and 27 eyes(77.14%)had leakage points in the upper part of the SRD.The mean thickness of the PROS layer above the RPE protuberance corresponding to the leakage point was 22.7 ± 9.0 um,and the mean thickness of the PROS layer in the SRD area outside the RPE protuberance was 66.1 ± 19.7 um.The difference was statistically significant(p < 0.01).The average distance from the upper edge of neuroepithelial detachment to the leakage point was 38.38% ± 2.35%。Conclusions:OCT and FFA are important methods for the diagnosis,differential diagnosis,treatment and follow-up of CSC.Mastering their imaging features is helpful for clinical diagnosis,treatment and understanding its pathogenesis.Through OCT imaging characteristics such as thinning of the PROS layer coexisting with RPE protuberance/ PED,fibrin exudation in the SRD area and its hyporeflective cavity,subsidence of the outer retinal layer,and RPE microrip,the leakage points can be preliminarily located,reducing the use of FFA in patients who are not suitable for laser photocoagulation,and also providing guidance for laser photocoagulation to seal the leakage points in patients who cannot undergo FFA examination due to pregnancy or allergy to fluorescein sodium.