Bilateral corneal perforation in familial amyloidotic polyneuropathy

We report the progression of bilateral central perforating ulceration in the cornea of a patient with familial amyloidotic polyneuropathy (FAP), also known as hereditary Portuguese amyloidosis, who received two corneal grafts in an interval of 6 years. The pathology of the original host and the grafted cornea is described.

Overall histology and immunolocalization of transthyretin, amyloid beta (Abeta), and epithelial and inflammatory markers were performed.

Corneal sensitivity and tear film were reduced. The grafted but not the original tissue contained amyloid deposits with transthyretin immunoreactivity. Epithelial and stromal thinning was accentuated in the graft, with epithelial dysplasia, hyperproliferation, and parakeratosis. Abundance of basement membrane material in hyperproliferative regions suggested recurrent attempts of wound healing. Activated keratocytes, ingrowth of vessels, infiltrated inflammatory, and immune cells reflect both acute and chronic inflammation.

Amyloid deposits may progressively reduce corneal sensitivity and damage epithelium and stroma. Corneal neuropathy, together with impaired tear film, may entail the pathology of dry eyes as a bystander effect, contributing to exacerbation of epithelial injury, deregulated proliferation, and parakeratosis. Once established, both acute and chronic inflammation may sustain progression of the corneal pathology.