Bitot's spots responsive and nonresponsive to vitamin A. Clinicopathologic correlations
A. Sommer, W. R. Green and K. R. Kenyon
Conjunctival biopsy specimens from patients with Bitot's spot responsive
and nonresponsive to vitamin A were studied by light and electron
microscopy. In both types, the lesions demonstrated keratinization with
granular cells, irregular maturation, inflammatory infiltration of the
conjunctival substantia propria, and loss of goblet cells. Only in the
responsive cases were these changes generalized. Prominent Bitot's spots
represented massive accumulations of Gram-positive bacilli and keratin
debris. Responsive cases improved histologically within seven days of
treatment, and goblet cells began to return within two weeks. These results
support our previous suggestions that there is little basis for attempting
to differentiate, clinically, between the two types of lesions and that at
least some nonresponsive lesions represent a persistent metaplastic change
induced during a prior episode of vitamin A deficiency.
