Diagnosis of lysosomal storage diseases by the ultrastructural study of conjunctival biopsies.

This ultrastructural study of conjunctival biopsies of 150 patients affected with various lysosomal storage disease allows us to demonstrate particular lesions in all the infantile phenotypes investigated so far. These alterations appear before the first clinical signs, suggest the possibility of such a disorder, and are often specific enough to propose an accurate diagnosis either because the lysosomes have a typical appearance or because their topographic distribution among the different conjunctival cell types is characteristic. As the morphologic approach is an obligatory step in the recognition of lysosomal storage diseases, we suggest concurrent use of conjunctival biopsy for the early screening and diagnosis of these disorders, as it is a very simple, easy, harmless technique, whose results are generally superior to those obtained by other methods.