Histochemistry of corneal granular dystrophy.

Since the introduction by Jones and Zimmerman (I 959, I 96 I) of a reliable histological scheme for the separate recognition of each of the three major categories of corneal stromal dystrophy, the way has been open for precise characterization of the nature of the lesions in each of these conditions. This has been largely accomplished for the macular and lattice dystrophies, the former having been shown to be an acid polysaccharide complex (Klintworth and Vogel, I964; Morgan, I966; Garner, i969b), and the latter to consist largely of amyloid (Seitelberger and Nemetz, I96I; Klintworth, 1967; Garner, 1969a). Relatively little is known, however, about granular dystrophy, and the several electron microscopical studies which have been reported in recent years have, on account of the widely differing descriptions, not been conspicuously successful in resolving the problem. Thus McTigue (I965, i967) described dense homogeneous masses which could not be resolved at magnifications of up to 71,000; workers in Japan (Kuwahara, Akiya, and Obazawa, I967; Matsuo, Fujiwara, and Ofuchi, I967) described rod-shaped structures; Sornson (I965) found both granular and fibrillar material; and Teng (I967) observed fine banded filamentous structures which he regarded as representing precollagen. Apart from the study of two cases of probable granular dystrophy, which were unusual in that the lesions were limited to the subepithelial region, by Goslar and Seitz (I96I) and Seitz and Goslar (I963, I965), there is a dearth of detailed histochemical information in this condition and it was for this reason that the present investigation was undertaken.