Multimodal imaging of bilateral retinal pigment epithelial immunoglobulin light chain deposition in patients with systemic immunoglobulin light chain deposition

To describe multimodal imaging of peculiar bilateral globular subretinal deposits and acquired serous retinal detachment in patients with systemic immunoglobulin light chain deposition. A retrospective observational case series. We examined six eyes in three patients (one with multiple myeloma, one with membranous nephropathy, and one with immunoglobulin A nephropathy) at the Eye and ENT Hospital of Fudan University. The patients presented with peculiar globular subretinal deposits along the retinal pigment epithelium (RPE)‒Bruch's membrane complex and acquired serous retinal detachment. Fundus appearance was documented with multimodal imaging, which included fundus photography, fundus autofluorescence, spectral domain optical coherence tomography (OCT), swept-source OCT (SS-OCT), en-face OCT, and SS-OCT angiography. Additional evaluations included serum protein electrophoreses, positron emission tomography computed tomography, and renal and bone biopsies to assess the primary diseases. Multimodal imaging, course, and prognosis of bilateral RPE immunoglobulin light chain deposition in patients with systemic immunoglobulin light chain deposition. Bilateral, multiple, speckled, or patchy RPE changes in the posterior fundus that corresponded to striking multifocal hyperautofluorescence on fundus autofluorescence and lumpy, globular hyperreflective deposits along the RPE‒Bruch's membrane complex were identified as characteristic features of bilateral RPE light chain deposition. These features may be accompanied by dense light chain deposits in the choriocapillaris and choroid vessels, diffuse choroidal thickening, and "angiographically silent" serous retinal detachment in patients with systemic immunoglobulin light chain deposition. We have documented the characteristic features, clinical course, and prognosis of bilateral RPE immunoglobulin light chain deposition in patients with systemic immunoglobulin light chain deposition. Appropriate evaluations, including serum protein electrophoresis and hematologic consultation, are recommended to manage patients with this fundus abnormality.