CONJUNCTIVAL IMPRESSION CYTOLOGY IN THE PRETERM INFANT AND ITS RELATION TO OUTCOME

The preterm infant is deficient in vitamin A (retinol) and this has be en implicated in the pathogenesis of chronic lung disease of prematuri ty. Conjunctival impression cytology (CIC) has been used in adults to assess retinol status. We aimed to assess the feasibility of performin g CIC in the preterm infant and to determine the significance of abnor mal CIC findings. CIC samples were collected during routine retinopath y screening, and classified as inadequate, normal, borderline normal o r abnormal. Ninety preterm infants were studied. Seventy four (82%) CI C specimens produced a positive yield, whereas 16 (18%) were inadequat e. Of the 74 adequate samples, 61 (82%) were normal or borderline norm al and 13 (18%) abnormal, Seventy-three CIC specimens were assessed by a second histopathologist with complete agreement on 64 (88%) samples and disagreement on 9 (12%) samples. Ten sets of conjunctival impress ions, taken from both eyes, gave identical results in all adequate sam ples. Birth weight was significantly lower in this abnormal group. Fou r infants (32%) in the abnormal group required treatment for retinopat hy compared to two (3%) in the normal/borderline normal group. (P < 0. 01) Conclusion Conjunctival impression cytology is simple and reproduc ible technique which maybe easily applied to the preterm infant. Abnor mal CIC is associated with retinopathy of prematurity requiring treatm ent.