Non-Hereditary Corneal Amyloid Deposition: A Case Series
JJ O'Brien, ME McLaughlin, N Laver. Tufts Medical Center, Boston, MA
Background: Corneal amyloid deposition can occur with localized eye disease. Amyloid has been associated with trauma, retinopathy of prematurity, trachoma and phlyctenular disease. A primary localized form of amyloid deposition, polymorphic amyloid degeneration, is a rare, bilateral, non-familial, sporadic disorder of the corneal stroma that is seen in people older than 50 years of age. Clinical findings of this particular disease include punctuate and filamentous, glass-like clear irregularly shaped corneal opacities in the middle and deep stromal layers that are refractile on retroillumination and do not form a distinct lattice pattern. Many corneal dystrophies are a result of mutations in the Transforming Growth Factor Beta Induced (TGFBI) gene that encodes for the BIGH3 protein (keratoepithelin), including lattice corneal dystrophies as well as autosomal dominant polymorphic corneal amyloidosis. AD polymorphic amyloid degeneration is caused by an A546D mutation in the TGFBI gene. Because of the genetic basis, corneal dystrophies are more likely to recur in grafts following corneal transplantation than other corneal disorders. In this series, we review cases of corneas with amyloid deposition without a clinical history suggestive of amyloid degeneration or lattice dystrophy. In these cases, the amyloid deposition is a localized eye disease seen in association with a previous surgery history, or scarring.
Design: Formalin-fixed, paraffin-embedded tissue sections were stained with hematoxylin-eosin, congo red, PAS, alcian blue, and Masson's trichrome in each case. Clinical history and histology were reviewed.
Results: Histological examination revealed corneal scarring, stromal edema, endothelial degeneration, mid-to-deep stromal small, scattered, fusiform, amorphous, eosinophilic deposits. The accumulations were congo-red positive and showed dichroic apple green birefringence, consistent with amyloid deposits. Masson trichrome and alcian blue stains were negative. Four cases were positive for amyloid deposits without a previous clinical history suggestive of lattice dystrophy. The 4 cases were submitted as corneal scarring, corneal edema, bilateral guttata suggestive of Fleck's dystrophy, and penetrating keratoplasty status-post extracapsular cataract extraction and posterior chamber intraocular lens implantation.
Conclusions: Corneas are frequently submitted for a variety of reasons, including graft failure, corneal scarring, and corneal edema. Because the hereditary corneal dystrophies tend to recur in corneal transplants, it is important to evaluate deposits incidentally identified in corneas.
Wednesday, March 24, 2010 1:00 PM
Poster Session VI # 262, Wednesday Afternoon