Multimodal retinal imaging in a Chinese kindred with familial amyloid polyneuropathy secondary to transthyretin Ile107Met mutation

To investigate the ocular phenotype and gene mutation of a Chinese pedigree with familial amyloid polyneuropathy (FAP) and vitreous amyloidosis. A Chinese pedigree with familial amyloid polyneuropathy and vitreous amyloidosis was recruited. Combined phacoemulsification, vitrectomy and intraocular lens implantation were performed on the right eye of the index patient. Ophthalmic investigations were performed before and after surgery. The DNA from the pedigree was sequenced for the transthyretin (TTR) gene. After vitrectomy, the best-corrected visual acuity of the patient improved from counting finger to 20/20. Red-free confocal ophthalmoscopy demonstrated perifoveal ring and several perivessel white sheaths. Optical coherence tomography (OCT) revealed cotton wool like reflections on the vitreoretinal interface. Electroretinogram and autofluorescence was normal. Amyloid was present in the vitreous specimen. A substitution of T to G at nucleotide 381 in exon 4 of TTR DNA (Ile107Met) was found. This mutation co-segregated with phenotype in the pedigree and was not detected in 200 controls. TTR Ile107Met mutation is associated with vitreous amyloidosis and FAP. OCT and red-free imaging are helpful in identifying amyloid deposits in the retina.