Differences in amyloid deposition in primary and recurrent corneal lattice dystrophy type 1

To report the histopathology of a case of recurrent corneal lattice dystrophy showing altered distribution of the corneal deposits in the recurrent disease compared with the original.

Clinical details and histopathology of the primary and repeat corneal grafts are reported.

A woman originally presented at age 28 years with reduced visual acuity and classic corneal lattice lines in both corneas and underwent bilateral corneal grafts. Recurrent disease was detected 20 years later as anterior haze and various-sized subepithelial opacities but no stromal lattice lines. Histology of the original corneas demonstrated amyloid deposits throughout the corneal stroma, typical of corneal lattice dystrophy. In the repeat grafts, amyloid deposits were confined to the basement membrane region of the anterior cornea and were almost entirely absent from the stroma of the cornea.

Recurrence of corneal lattice dystrophy is widely recognized to occur, but the pathology of the recurrent disease is not well documented in the literature. This case report highlights that there may be a difference in the distribution of the deposits when the disease recurs. We postulate that the reason for this difference may be that donor keratocytes survive long enough in the transplanted cornea to prevent build-up of abnormal keratoepithelin, the product of the mutated gene in type 1 corneal lattice dystrophy. By contrast, the epithelium, being replaced by host epithelium shortly after grafting, is still producing abnormal protein. The differences in the pattern of deposits may have important clinical implications, particularly regarding treatment modalities in recurrent disease.