Vitamin E prevents changes in the cornea and conjunctiva due to vitamin A deficiency.

PURPOSE

To determine whether vitamin E can prevent changes in the cornea and conjunctiva due to vitamin A deficiency.

METHODS

Male infant rats from normal mothers were weaned at 20 days of age and divided into three groups: in group 1, A(-), rats were fed a vitamin A-deficient diet; in group 2, A(-)E(+), rats were fed a vitamin A-deficient diet and injected intraperitoneally with 15 mg of vitamin E per week; group 3 rats were normal controls. At 13 weeks of age, the corneal and conjunctival changes were examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

RESULTS

SEM showed more fine microvilli and clear cells in the most superficial epithelial layer of the cornea and conjunctiva in A(-)E(+) rats than in that of A(-) rats. Numerous secretory granules were seen in the goblet cells of the conjunctiva of A(-)E(+) rats, but in A(-) rats there was a total absence of conjunctival goblet cells. TEM showed a severely keratinized corneal surface in A(-) rats. On the other hand, the corneas of A(-)E(+) rats were almost normal in appearance. The conjunctivae of A(-) rats had superficial epithelial keratinization, scarce goblet cells, and many keratohyalin granules in the epithelium and dark cells, while in the conjunctivae of A(-)E(+) rats there were numerous secretory granules in goblet cells and some dark cells.

CONCLUSION

The present study suggests that vitamin E has a protective effect against the corneal and conjunctival damage caused by vitamin A deficiency.