Granular corneal dystrophy with early stromal manifestation. A clinical and electron microscopical study.

We describe a family tree from central Finland with 19 members of which 10 had typical granular corneal dystrophy (Bücklers 1938). This granular dystrophy seems to start from the subepithelial and anterior stromal region. In quite early ages the granules spread not only into the midstromal layers but also into the most posterior stroma between the stromal lamellae and Descemet's membrane. Corneal epithelial erosions were not noticed in this family. The central cornea was mostly affected and 2-3 mm of the corneal periphery was clear. No endothelial changes were found from the corneal midperiphery by specular microscopy. To date, two female patients have needed penetrating keratoplasty; one in her late thirties and the other in her early forties. Their corneal buttons were studied by electron microscopy and histochemically. Granular material was found between the stromal lamellae and also inside the stromal keratocytes. Bowman's membrane was disrupted and degenerated in the areas where the deposits were situated in the subepithelial region. Recurrence of the disease was observed in the corneal transplants of the two operated patients 3 years postoperatively, starting again in the subepithelial region and mostly in central areas of the transplant. This disease entity seems to be different from the granular dystrophy also reported from Finland by Forsius et al. (1983).