Clinical and Histopathologic Studies of Two Families with Lattice Corneal Dystrophy and Familial Systemic Amyloidosis (Meretoja Syndrome)

Abstract

Lattice corneal dystrophy associated with familial systemic amyloidosis (Meretoja syndrome) has rarely been described other than in patients of Finnish origin. The authors report two North American patients with this disease who manifest blepharochalasis, lattice corneal dystrophy, open-angle glaucoma, and cranial neuropathy. In one patient, a corneal intraepithelial and subepithelial pseudodendrite was managed by superficial keratectomy, and this same patient benefited from surgical brow suspension for facial muscular weakness. In the second patient, penetrating keratoplasty was complicated by a neurotrophic persistent epithelial defect. Corneal tissue from both superficial keratectomy and penetrating keratoplasty exhibited ultrastructurally characteristic amyloid filaments and associated elastoid material. Transmission electron microscopy of conjunctiva and skin biopsies similarly revealed amyloid deposits associated with most basement membranes, the perineurium and endoneurium of most peripheral nerves, and the intima and media of arteries. By immunoperoxidase staining, the corneal amyloid deposits were positive for the amyloid P-component protein but negative for the nonimmunoglobulin amyloid A protein and prealbumin. Serum prealbumin and amyloid A related protein were normal.