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Purpose To describe a case of AA amyloidosis which produced an orbital inflammatory response with a novel presentation. Methods Case report. Results A 24 year-old Caucasian female with a history of intravenous (IV) heroin use was hospitalized for tricuspid valve endocarditis and methicillin resistant Staphylococcus aureus bacteremia, as well as acute renal failure. She received hemodialysis and IV daptomycin and had negative blood cultures for 3 weeks, when she developed sudden bilateral orbital swelling and blurred vision. Visual acuity was 20/200 in the right eye (OD) and 20/400 in the left eye (OS). Examination revealed proptosis, conjunctival chemosis and desiccation, optic disc swelling, creamy choroidal infiltrates and inferiorly located exudative retinal detachments in both eyes (OU). Multimodal imaging demonstrated thickening of the sclera, choroid and choriocapillaris as well as outer retinal disruption, subretinal fluid and deposits of hyperfluorescent debris within the choriocapillaris, outer retina and vitreous. Oral prednisone at 60 mg per day resolved the choroidal infiltrates and exudative detachments. Persistent nephrotic syndrome called for a renal biopsy, which demonstrated AA amyloidosis. Conclusion - Orbital and choroidal AA amyloidosis can induce a local inflammatory response manifesting as orbital swelling, papillitis, posterior scleritis, choroiditis and exudative retinal detachment, which responds to steroid therapy. The underlying pathology is likely a reactive inflammation and vaso-occlusive process involving the choriocapillaris and orbital vasculature to the presence of amyloid fibrils.

PURPOSE To describe a case of non-syndromic retinitis pigmentosa (RP) caused by presumed compound heterozygous A615T and T522M mutations in HGSNAT, characterized by bilateral cystoid macular edema (CME) and retinal neovascularization (NV). METHODS Case report. The patient underwent clinical evaluation, multimodal imaging and Next Generation panel sequencing. In silico analysis was performed with PolyPhen-2, SIFT and Mutation Taster. Segregation analysis was not available. RESULTS A 35 year-old hypertensive man presented with nyctalopia, photopsia, and difficulty reading for six months. He had no family history of visual deficits. Best-corrected visual acuity (BCVA) was 20/25 in the right eye (OD) and 20/20 in the left eye (OS). Examination revealed mid-peripheral bone spicules and macular NV in both eyes (OU). Multimodal imaging demonstrated CME, ellipsoid band loss outside the central macula, and leakage from the NV in both eyes. Sequencing detected four mutations in three genes, including two heterozygous mutations in HGSNAT (c.1843G>A, p.A615T and c.1565C>T, p.T522M). A615T is a pathogenic, hypomorphic mutation. T522M has not been previously phenotypically described. It is predicted damaging by in silico analysis and occurs at a conserved position near the eighth transmembrane domain, adjacent to residues in which missense mutations result in protein misfolding. CONCLUSION This is, to our knowledge, the first reported case of retinal NV in a case of non-syndromic RP due to HGSNAT mutation. The T522M variant likely functions as a severe mutation alongside the hypomorphic A615T mutation. These findings expand the genotypic and phenotypic spectrum of non-syndromic RP.