OCTA evaluation of treatment-naïve flat irregular PED (FIPED)-associated CNV in chronic central serous chorioretinopathy before and after half-dose PDT

Background To qualitatively and quantitatively evaluate the features of treatment-naïve flat irregular pigment epithelial detachment (FIPED)-associated choroidal neovascularization (CNV) in chronic central serous chorioretinopathy (CSC) using swept-source (SS) optical coherence tomography angiography (OCTA) before and after half-dose photodynamic therapy (PDT). Methods Retrospective case series. The multimodal imaging data of the eyes with FIPED-associated CNV in chronic CSC were reviewed. The features of FIPED-associated CNVs were evaluated by SS-OCTA. Results Records of twenty-one patients (21 eyes) were reviewed. The mean age was 56.62 ± 6.87 years. After half-dose PDT, all patients have improved best spectacle-corrected visual acuity from 0.49 at baseline to 0.25 at 6-month visit, and subfoveal choroidal thickness decreased with subretinal fluids absorbed. By OCTA, the features of CNV at baseline included long filamentous linear vessels (21/21), branching into other large mature vessels with rare anastomoses (21/21); and/or a ‘dead tree’ appearance at the vessel’s termini (20/21); and no perilesional hypointense halo (21/21). Compared to those at baseline, the mean vessel density of CNV showed no significant change at 1-,3-,6-month follow-up, while the mean area of CNV was significantly larger at the 6-month follow-up ( p = 0.013). Conclusions OCT angiography allows to qualitatively and quantitatively evaluate CNV in chronic CSC. The features of FIPED-associated CNV on OCTA illustrated its quiescent characteristic and further guided therapy. Half-dose PDT showed favorable effects on chronic CSC complicated with FIPED-associated CNV.