Conjunctival impression cytology with transfer in the assessment of vitamin A status in Nigerian children

OBJECTIVE: To determine vitamin A status by conjunctival impression cytolog y with transfer (CIC-T) and assess its ability to predict low and deficient serum retino concentrations. STUDY DESIGN: CIC-T was performed on 128 healthy, well-nourished and 230 ma lnourished children aged under 6 years by a 3-5-second application of cellu lose acetate paper to each bulbar conjunctiva followed by transfer of the a dhered cells onto glass slides. The slides were stained with Alcian green 2 GX, and smears were classified as normal, borderline normal, borderline abn ormal and deficient. Corresponding serum retinol In,els were determined in each subject, RESULTS: The results showed that CIC-T is a simple procedure with a failure rate gf 7.3% caused by tearing and agitation. The power of CIC-T to predic t vitamin A status varied with both the CIC-T smear classification used and serum retinol concentration threshold. CIC-T smear classification as abnor mal and normal appears to be the most robust and predictive of serum retino l, < 10 and > 10 < 20 mu g/dL, respectively. CONCLUSION: The simplicity, sensitivity and specificity of CIC-T suggest th at this procedure is a good screening tool for epidemiologic survey of vita min A status.