Unusual cause of retinal vasculitis

A 39-year-old non-diabetic and non-hypertensive Asian male presented with bilateral progressive diminution of vision. He had a visual acuity of 6/24 with normal intraocular pressure in both eyes. Ocular examination revealed corneal [Fig. 1a], lenticular [Fig. 1b], vitreous opacities [Fig. 1d] with multiple hemorrhages and cotton wool spots (CWS) [Fig. 1e and f] in both eyes. The patient gave a history of burning paresthesia and numbness in both feet with a history of similar illness in his father, who passed away in his early 40s.Figure 1: (a) is an anterior segment photo showing corneal opacities s/o corneal lattice dystrophy (yellow arrow), (b) shows posterior lenticular opacities (pseudopodia lentis [yellow arrow]), (c) shows normal brain imaging, and (d) shows needle-shaped vitreous opacities (yellow arrow). (e and f) shows multiple hemorrhages and cotton wool spots along with preretinal deposits (blue arrow). (g and h) is the fundus fluorescein angiogram of the left eye showing perivascular focal and diffuse leakage (blue arrows) in late phase suggestive of vessel wall staining or leakageQ. Which examination finding is typical of the diagnosis? Corneal opacity as seen in Fig. 1a Lens and vitreous opacities in Fig. 1b and d Fundus imaging/fluorescein angiography Brain imaging findings Findings: Ocular findings like lattice corneal dystrophy [Fig. 1a], lenticular opacities (pseudopodia lentis which is diagnostic of amyloidosis; Fig. 1b), needle-shaped vitreous opacities [Fig. 1d], sensorimotor dysfunction, and family history were suggestive of the diagnosis of amyloidosis. Fundus fluorescein angiography (FFA) revealed early blocked fluorescence in areas of hemorrhage, and CWS with perivascular staining in the late phase [Fig. 1g and h] revealed retinal angiopathy. Neurological examination was suggestive of axonal sensorimotor polyneuropathy although brain and vascular imaging was normal [Fig. 1c]. Investigations revealed nephritic range proteinuria but serum and urine protein electrophoresis failed to reveal an M band. Amyloidosis was strongly suspected based on clinical findings, so a duodenal biopsy and abdominal fat aspirate were done. However, it turned out to be negative for amyloid, so a renal biopsy was planned. It revealed minimal change disease (MCD) but the absence of amyloid deposits. The patient refused vitreous biopsy. Sural nerve biopsy revealed congophilic and apple green birefringent deposits in the axons and myelin sheath with sparing of vascular and connective tissue, diagnostic of amyloid. Retinal findings in our case were suggestive of retinal amyloid angiopathy (RAA), which is a rare manifestation of amyloidosis. Genetic testing was advised but not done due to financial constraints. Answer: B Diagnosis: Familial transthyretin-associated amyloidosis. Discussion RAA is an uncommon retinal vasculopathy secondary to hereditary transthyretin amyloidosis (hATTR) that can lead to severe visual impairment. Clinical manifestations of RAA include retinal microaneurysms, CWS, retinal neovascularization, and rarely neovascular glaucoma.[1] FFA features of RAA include retinal arterial occlusion, perivascular staining, arteriovenous anastomosis, and neovascularization. Histopathological studies show the harmful effects of amyloid deposits on endothelial cells, leading to capillary occlusion and destruction of the endothelial barrier and the aforementioned fundus appearance.[1–3] In our case, the typical lens and vitreous opacities helped in strongly suspecting and reaching the diagnosis of amyloidosis. Pseudopodia lentis are the punctuate dots present on the posterior capsule of the lens, at the site of attachment of vitreous amyloid material and are typical of amyloidosis.[4] Therefore, clinical examination is the first crucial step, followed by FFA, vitreous, and nerve biopsy as necessary. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship: Nil. Conflicts of interest: There are no conflicts of interest.