RESUMEN
Ocular signs and serum vitamin A concentration are commonly used tor the diagnosis of vitamin A deficiency. Recently, impression cytology was suggested as a method for early detection of vitamin A status. Twenty patients with normal eyes and digestive disease, and 111 children with normal eyes were evaluated by serum vitamin A concentration, relative-dose-response and conjunctival impression cytology test. About 90% of the patients with normal conjunctival impression cytology has normal vitamin A status. About 70% of the patients with abnormal conjunctival impression cytology has abnormal vitamin A status despite their seemingly normal clinical ocular examination, and so did the children. These results suggest that impression cytology can identify individuals with preclinical vitamin A deficiency.