Define Clinical Assessment For Vitamin A?

Clinical features of deficiency occur as ocular and extra ocular lesions. Ocular lesions affect the posterior segment of the eye initially with impairment of dark adaptation and night blindness (twilight blindness). Xerosis of the conjunctiva is the first sign seen on clinical examination. This leads to Bitot's spots. Keratomalacia is the last stage. Extra-ocular lesions include dry scaly skin (follicular hyperkeratosis), toad skin or phrynoderma. There is increased susceptibility to infections. The WHO  classification for assessment of vitamin A status is summarized  in Table.