Granular corneal dystrophy. Visual results and pattern of recurrence after lamellar or penetrating keratoplasty.

BACKGROUND: Granular corneal dystrophy is a rare indication for corneal transplantation. Both penetrating and lamellar keratoplasty have been recommended, but because granular corneal dystrophy is known to recur within the donor material and multiple grafts may be necessary, the best surgical option has not been clearly established. The cellular cause of the dystrophy is unknown and the authors hypothesized that the rate and pattern of recurrence within lamellar and penetrating grafts might give clues to its etiology.
METHODS: The authors compared the visual outcome, rate, and pattern of recurrence after 20 penetrating keratoplasties and 11 lamellar keratoplasties for granular corneal dystrophy.
RESULTS: Penetrating keratoplasty and lamellar keratoplasty have a good visual outcome in granular corneal dystrophy. Visual acuities after both procedures were not statistically different. Recurrence of the dystrophy within the graft material was almost universal within 4 years. It first appeared centrally and superficially, occasionally adopting a vortex pattern suggesting epithelial involvement. The recurrence-free interval was independent of size and type of graft performed.
CONCLUSION: The authors recommend lamellar keratoplasty as a primary procedure in managing visually disabling granular corneal dystrophy if the deposits are limited to the superficial cornea. This is particularly applicable in younger patients in whom multiple procedures may be necessary over a lifetime due to recurrence of the dystrophy, and the lower morbidity rate associated with lamellar keratoplasty becomes appreciable. Although granular corneal dystrophy generally is classified as a stromal dystrophy, the pattern of recurrence is more consistent with an epithelial or tear-borne abnormality than a disease of the stromal keratocyte.