The overlapping spectrum of flat irregular pigment epithelial detachment investigated by optical coherence tomography angiography

Purpose To describe the OCT angiography characteristics of flat irregular pigment epithelial detachments (PEDs), an overlapping tomographic feature of various macular disorders. Methods Consecutive patients with a dimpled retinal pigment epithelium profile on OCT, referred for a second opinion, were enrolled. Fluorescein (FA) and indocyanine green angiography (ICGA) were performed in all patients and compared to previous examinations, when available. In all patients, enhanced depth imaging-OCT and OCT angiography were performed upon referral and at subsequent follow-ups. Results Twenty-five eyes from 25 patients (9 women and 16 men, mean age of 63.4 years) were enrolled. The diagnoses of CSCR were already established by the referring physicians in 10 patients, acute in 15% and chronic in 26%; 48% of patients were referred with a diagnosis of type 1 CNV, and 11% of CSCR complicated by CNV. After performing OCT angiography, 2 masked examiner identified 7 type 1 CNV (29%), 18 eyes with pachychoroid disease of which 31% pachychoroid pigment epitheliopathies (PPEs) at baseline evolved to CSCR, 22% PPE at baseline evolved to pachychoroid neovasculopathy, 18% pachychoroid neovasculopathy stable. Conclusion Central serous chorioretinopathy, type 1 CNV, and the pachychoroid spectrum of diseases cause abnormalities in the choroidal circulation that make the overlying RPE dysfunctional, resulting in flat irregular PED. Discrimination between avascular and vascular flat irregular PEDs is crucial for a good visual outcome, but since chronic alterations of the RPE can compromise the diagnostic specificity of FA and ICGA, OCT angiography may become a fundamental tool to differentiate these clinical entities.