Sir,

The common ocular manifestations of amyloidosis include deposition in the ocular adnexa, conjunctiva, cornea, glaucoma, and vitreous.1 Retinal and choroidal involvement is rare.

Case report

A 35-year-old woman complained of progressive nyctalopia. She had previously been diagnosed of secondary AA amyloidosis affecting her kidneys, bone marrow, thyroid gland, and colon (confirmed on biopsy). Despite extensive investigations no underlying disease was identified.

Her vision was 6/6 in each eye. Ocular adnexae, anterior segments, and intraocular pressures were normal. Fundoscopy showed widespread small drusen-like white deposits, diffuse pigmentary changes, and microaneurysms (Figure 1). Autofluorescence imaging showed a diffuse speckled pattern (Figure 2a). Fluorescein angiography (FA) showed multiple microaneurysms (Figure 2b). Indocyanine green (ICG) angiography showed dilated large choroidal vessels with variable calibre, and hyperfluorescence and staining along retinal and choroidal vessels (Figure 2c and d). OCT showed normal foveal thickness. Electrophysiological testing suggested maculopathy (reduced P50 on pattern ERG; increased latency from central and peripapillary rings from both eyes on multifocal ERG) (Figure 3a). Full-field ERG showed decreased and delayed scotopic and photopic responses with borderline maximal responses, suggesting generalized photoreceptor dysfunction (Figure 3b).

Figure 1
figure 1

Fundus photography showing widespread small drusen-like white deposits and diffuse pigmentary changes.

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Figure 2
figure 2

(a) Speckled pattern on autofluorescence imaging. (b) FFA showing multiple microaneurysms. (c) ICG showing variable-calibre choroidal vessels and (d) staining along retinal and choroidal vessels.

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Figure 3
figure 3

(a) Multifocal ERG tracing showing reduced and delayed responses from the central rings. (b) Full-field ERG tracings showing decreased and delayed scotopic and photopic responses, and borderline maximal responses.

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Comment

Only a few cases of retinal changes have been described in FAP.2, 3, 4 These described pinpoint white deposits, retinal vascular sheathing, microaneurysms, and scattered retinal haemorrhages. Angiographic changes similar to our patients were seen (vascular closure, focal staining, and microaneurysms on FA; hyperfluorescence and staining along choroidal and retinal vessels on ICG).

Although the fundal changes could potentially be due to an underlying disease causing the secondary amyloid, they are strikingly similar to those described in FAP and amyloid AL. We propose that the changes result from amyloid deposition in the choroidal and retinal vasculature, which causes ischaemia and further photoreceptor and macular dysfunction. The microaneurysms and pigmentary changes are likely the result of retinal ischaemia. The pinpoint white deposits are similar in appearance to drusen and probably reflect amyloid deposition within the retina, resulting in the speckled AF pattern. Indeed Aβ amyloid has been identified in drusen and may have a role in the pathogenesis of age-related macular degeneration.5 These new findings may help in further understanding the ocular involvement of amyloidosis in forms other than FAP.