[Observation of special stain and ultrastructure of lattice, granular and macular corneal dystrophy]

Abstract

Objective: To investigate the histopathological changes of lattice, granular and macular corneal dystrophy.

Methods: Corneal buttons were obtained from penetrating keratoplasty due to severe corneal dystrophy, and their sections and ultrathin sections with several special stains were observed under a light microscope (LM) and electron microscope (EM).

Results: In cases with lattice dystrophy, the stromal fusiform deposits seen under LM were confirmed to be amorphous materiel with filaments by EM and stained positively for Masson trichrome, PAS and Congo red. In cases with granular dystrophy, the granular or bread debris deposits found between laminae under LM were extracellular material observed by EM and they were stained positively for Masson trichrome and alcian blue. In cases with macular dystrophy, the stromal spheroid or macular deposits were seen under LM, and there were numerous vacuoles containing fibrils and granules in the cytoplasm of keratocytes and accumulative amorphous material in the stroma under EM; the deposits were positive for colloidal iron and alcian blue stain.

Conclusion: In corneal lattice dystrophy, there are amyloid deposits; in granular dystrophy, there are extracellular material deposits; and in macular dystrophy, there is mucopolysaccharide accumulation.