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Vitamin E prevents changes in the cornea and conjunctiva due to vitamin A deficiency
Azusa Fujikawa1, Huaqing Gong, Tsugio Amemiya
1Department of Ophthalmology and Visual Sciences, Graduate School of Biomedical Sciences, Nagasaki University, 1-7-1 Sakamoto, 852-8501 Nagasaki, Japan. f0937@cc.nagasaki-u.ac.jp
Insights
Vitamin E supplementation protected rat corneas and conjunctivas from damage caused by vitamin A deficiency. This suggests vitamin E may prevent ocular surface changes linked to vitamin A deficiency.
Area of Science:
- Ophthalmology
- Nutritional Science
- Cell Biology
Background:
- Vitamin A deficiency is a leading cause of preventable blindness worldwide.
- Ocular surface manifestations of vitamin A deficiency include xerophthalmia, characterized by corneal and conjunctival changes.
- The role of vitamin E in mitigating these specific ocular surface changes requires further elucidation.
Purpose of the Study:
- To investigate the potential protective effects of vitamin E against corneal and conjunctival alterations induced by vitamin A deficiency in a rat model.
- To compare the ultrastructural changes in the cornea and conjunctiva of vitamin A-deficient rats with and without vitamin E supplementation.
Main Methods:
- Male infant rats were divided into three groups: vitamin A-deficient (A-), vitamin A-deficient with vitamin E supplementation (A-E+), and normal controls.
- Rats were fed experimental diets and vitamin E was administered intraperitoneally weekly.
- Corneal and conjunctival tissues were analyzed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) at 13 weeks of age.
Main Results:
- Vitamin A-deficient rats supplemented with vitamin E (A-E+) exhibited more microvilli and clearer epithelial cells on the cornea and conjunctiva compared to vitamin A-deficient rats (A-).
- Goblet cells in the conjunctiva of A-E+ rats contained secretory granules, whereas A- rats showed a complete absence of goblet cells.
- TEM revealed severe corneal keratinization in A- rats, while A-E+ rats had near-normal corneas; conjunctival keratinization and abnormal epithelial cells were reduced in A-E+ rats.
Conclusions:
- Vitamin E demonstrates a significant protective effect against the development of corneal and conjunctival damage associated with vitamin A deficiency.
- These findings highlight the potential therapeutic role of vitamin E in managing ocular surface complications of 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.