RESUMO
Impression cytology has been suggested as a relatively simple, cheap, practical and non invasive technique for documenting physiologically significant vitamin A deficiency. The vitamin A status of 41 patients was evaluated by serum retinol concentration by high power liquid chromatography (HPLC) and conjunctival impression cytology was performed on each child. All children with normal vitamin A status had normal conjunctival impression cytology. The sensibility of this method was 100%. However, in the 8 vitamin A deficient patients by impression cytology, only 6 of them showed low serum vitamin A levels. Impression cytology appears to detect preclinical vitamin A deficiency that this technique may by of potential usefulness as a screening tool for preclinical vitamin A deficiency populations.