OCULAR MANIFESTATIONS OF MONOCLONAL IMMUNOGLOBULIN LIGHT CHAIN DEPOSITION DISEASE

To demonstrate unusual retinal findings in a patient with progressive renal failure due to idiopathic monoclonal immunoglobulin light chain deposition disease, using multimodal imaging.

Observational case report of a 43-year-old white man with renal failure due to light chain deposition disease. His course over 6 years was documented with multimodal imaging including fundus photography, fundus autofluorescence, fluorescein angiography, and spectral domain optical coherence tomography. Additional evaluations included ocular ultrasound, electroretinography, positron emission tomography, serum protein electrophoreses, skeletal surveys to detect osteolytic lesions, and renal, liver, and rectal biopsies in search of amyloid.

The patient's ocular course mirrored the severity of his renal dysfunction for which he required a renal transplant. Changes observed in the native kidney recurred in the transplant 2 years later, as evidenced by immunohistochemistry, revealing thick linear deposits of kappa chains, with no complement, overlying the glomerular basement membrane. The systemic workup was negative for amyloid but showed an overwhelming ratio of kappa to lambda light chains on serum protein electrophoreses and no clinical signs of plasma cell dyscrasias, all consistent with idiopathic light chain deposition disease. The patient presented with a generalized, bilateral "leopard-spot" fundus appearance on fundus autofluorescence, striking globular subretinal deposits on spectral domain optical coherence tomography, and subfoveal subretinal fluid without retinal pigment epithelium detachment or choroidal effusions. The subfoveal fluid did not respond to intravitreal injections of antiangiogenic agents or steroids but resolved after renal transplantation. A temporary posttransplant visual improvement was associated with lessening of the subretinal drusenoid deposits demonstrated by multimodal imaging. The terminal vision deterioration was associated with amorphous, vitelliform-like material deposition and atrophic changes.

This case may illustrate a resemblance in the renal glomerulus basement membrane and retinal pigment epithelium-Bruch membrane complex, because the authors observed deposits of excess monoclonal kappa chains manifesting as extracellular, proteinaceous aggregates on the basement membrane of the glomerulus, and striking, globular subretinal deposits that overlay a thickened retinal pigment epithelium-Bruch membrane complex. The ocular lesions' refractoriness to intravitreal treatments could be attributed to the fact that they represent proteinaceous aggregates similar to those documented in the glomeruli. This is the first report of generalized, large, subretinal drusenoid deposits and their course, as documented through multimodal imaging, paralleling the chronology of systemic changes in a patient with light chain deposition disease.