Vitamin A or retinol is a fat-soluble substance stored in body organs, principally the liver.
It is released as needed into bloodstream, becoming available for use by cells throughout the body, including those of the eye. It has important functions related to vision and reproduction.
Vitamin A deficiency occurs in persons with poor diet and lacking vegetables. When there is depletion of vitamin A in liver, the earliest sign is night blindness that is impaired dark of adaptation.
Xerophthalmia is caused by deficiency of vitamin A. Xerophthalmia is a term to cover all the ocular manifestation of vitamin A deficiency, including not only the structural changes affecting the conjunctiva cornea and occasionally retina, but also the biophysical disorders of retinal rod and cone function that are attributable to vitamin A deficiency.
It produces one or more severe eye diseases/disorders.
While adults store vitamin A in liver, the infants do not possess adequate stores of vitamin A. Xerophthalmia thus affects large number of children but rarely adults.
If not treated in time, it can lead to permanent blindness.
Xerophthalmia and vitamin A deficiency