Familial amyloidotic polyneuropathy (FAP) type I is an inherited disorder with autosomal dominant transmission, related to mutant transthyretin (TTR) and characterized by systemic extracellular accumulation of amyloid. TTR is mainly synthesized in the liver, but there is also production in the retinal pigment epithelium. One point mutation in which a methionine residue replaces the valine residue at position 30 (TTR Val30Met) is the most frequent mutation associated to FAP and it is present in several large foci around the world, namely Portugal, Japan, Sweden and Balearic Islands. This condition was first described in Portugal in 1952, when Corino de Andrade reported a peculiar neuropathy characterized by ascending sensory-motor loss and severe autonomic dysfunction.

Intra-ocular synthesis of TTR originates amyloid deposition in several ocular tissues. Most frequent ophthalmic manifestations of FAP type I include abnormal conjunctival vessels, keratoconjunctivitis sicca, irregularities on anterior lens surface and border of the pupil, change of pupillary shape (scalloped pupil) and light reflex, vitreous opacities and secondary glaucoma. Retinalamyloid microangiopathy is less frequent and related to advanced stage of the disease. Vitreous deposits of amyloid may be seen associated to other ocular changes, but it has been also described as the earliest, isolated symptom of the disease, particularly in late onset cases (when disease begins after 50 years old). Scalloped pupil and dense vitreous opacities are pathognomonic of FAP and has to be recognized by ophthalmologist.

Liver transplant (LT) and systemic treatment like tafamidis improve life expectancy of patients with FAP but LT does not influence the progression of ocular involvement and ophthalmic effects of tafamidis are still unknown.