Role of conjunctival impression cytology in detecting sub-clinical vitamin A deficiency

Introduction: Vitamin A is an essential nutrient required for normal vision, epithelial maturation, and immunological responses. Vitamin A deficiency (VAD) is a major public health problem in many developing countries, including India, but only 5%-10% show clinical evidence. Studies have shown that subclinical vitamin A deficiency is associated with increased mortality and morbidity.
Materials and Methods: Children suspected of VAD, who were attending the Pediatric OPD at VIMS, Ballari, were studied. Those children with classical features of VAD were excluded. Conjunctival impression was taken using cellulose acetate filter paper, stained, and studied for epithelial changes, which were graded according to the Nelson grading system.
Results: Out of 250 children, 140 (56%) were male and 110 (44%) were female. All age groups were equally affected and had subclinical VAD with an average of 81.2%. The occurrence of subclinical VAD was significantly associated with severe grades of PEM, recurrent LRTI, diarrhea, UTI, measles, etc. Nelson’s grading for Conjunctival imprint cytology (CIC) was effective in detecting more than 80% of all cases of sub-clinical VAD.
Conclusion: Subclinical VAD without ocular manifestations was largely prevalent in a suspected group of children, more so in children of low socio-economic status. Conjunctival Impression cytology was able to detect the majority of these cases, initiate early management of these subclinical cases, and thus reduce the mortality and morbidity associated with VAD.