Spectral domain-optical coherence tomography retinal biomarkers in choroidal neovascularization of multifocal choroiditis, myopic choroidal neovascularization, and idiopathic choroidal neovascularization

Objective To use optical coherence tomography (OCT) to compare retinal biomarkers of choroidal neovascularization (CNV) secondary to multifocal choroiditis (MFC), myopic choroidal neovascularization (mCNV), and idiopathic choroidal neovascularization (ICNV) and to provide a basis for its clinical diagnosis and treatment. Methods In this retrospective case study, patients admitted to the Second Hospital of Hebei Medical University between January 2018 and January 2021 who were initially diagnosed with CNV secondary to MFC, mCNV, and ICNV were categorized into groups, by disease, for analysis. Spectral domain-OCT (SD-OCT) was used to describe and measure the morphological characteristics of CNV lesions in each group. The retinal biomarkers of CNV in MFC, mCNV, and ICNV were compared. Results Sixty-eight patients (71 eyes) were included and all eyes were diagnosed with active type 2 CNV. The MFC group had higher refraction than the ICNV group (P2 < 0.05). The choroidal thickness (CT) and CNV diameter of the MFC group were significantly greater than those of the mCNV group (P1 < 0.05). The number of eyes with sub-retinal fluids (SRF) and a "pitchfork sign" was significantly greater in the MFC group than in the mCNV group (P1 < 0.05). There was a significant difference only in CT) values between the MFC and ICNV groups (P2 < 0.001), but not in the other observation indicators (P2 > 0.05). Conclusions OCT biomarkers, such as the diameter of the CNV, SRF, the "pitchfork sign," and CT under CNV are useful in distinguishing CNV secondary to MFC from mCNV, which can allow the timely selection of treatment in some difficult cases. There were no differences between the MFC group and ICNV group except in refractive error, which indicates that some ICNV cases may be an early stage of a type of occult chorioretinitis. Long-term follow-up is needed for ICNV patients to confirm whether there is any potential inflammation. Key messages Sometimes, it is difficult to separate MFC with CNV from myopic CNV and ICNV in clinical. OCT biomarkers, such as the diameter of the CNV, SRF, the "pitchfork sign," and CT under CNV are useful in distinguishing CNV secondary to MFC from mCNV. There were no differences between the MFC group and ICNV group except in refractive error.