Ocular changes in familial amyloidotic polyneuropathy with dense vitreous opacities.

Familial amyloid polyneuropathy (FAP) is a hereditary disease which eventually causes serious ocular problems. Seven eyes from patients with FAP 1 were vitrectomised, and the insoluble proteins from the vitreous were purified, the amyloid protein isolated, and the prealbumin characterised with a monoclonal antibody against amyloid fibril protein. Before surgery, visual acuity was very poor, due to abundant deposits in the vitreous, frequently attached to the posterior lens capsule. The pupil had peculiar indentations and the pupillary reflexes were abnormal. Intraocular pressure (IOP) was at the upper limit of normal. In the ocular fundus an intraretinal perifoveal gray ring was sometimes seen. Vitrectomy improved visual acuity, but the reappearance of vitreous deposits reduced it to 8.8/10 after 33.4 months, when treatment was needed for most of the eyes to control IOP. Amyloid and the mutant form of prealbumin characteristic of FAP 1, TTR Met 30, were shown to be present in the vitreous.