Conjunctival impression cytology in the preterm infant and it's relation to outcome

Abstract

Conjunctival impression cytology is simple and reproducible technique which maybe easily applied to the preterm infant. Abnormal CIC is associated with retinopathy of prematurity requiring treatment.

Further analysis of the size and shape of cells obtained by impression cytology from the exposed portion of the human bulbar conjunctiva

“…Images in the literature indicate that similar confluent layers of cells can be obtained if a glass rod is used to exert pressure on an unsupported filter after applying it to the conjunctival surface (Nelson, 1982;Nelson et al, 1983;Adams et al, 1988;Knop and Bewitt, 1992a;Bhatia et al, 1995;Dogru et al, 1998). If the tip of a pair of forceps or tweezers, or similar, is used to exert pressure between the conjunctival surface and an unmounted filter then less confluent and irregular sheets of cells seem to be the more likely yield (Egbert et al, 1977;Tseng, 1985;Pfugfelder et al, 1990;Rolando et al, 1990;Knop and Brewitt, 1992a,b;Rivas et al, 1993;Hughes et al, 1997;Blodi et al, 1998;Blades et al, 1998), although reasonably sized sheets of cells can be obtained (Rivas et al, 1992;Blades et al, 1998;Bizzari et al, 1998a). Other investigators, even using a glass rod, have however reported difficulty in obtaining adequate numbers of cells off the bulbar conjunctiva (Connor et al, 1991).…”

Citologia de impressão da superfície ocular: técnica de exame e de coloração

“…As amostras são fixadas, coradas e examinadas em laboratório, usando-se um método modificado para a citologia da superfície ocular. Esta técnica auxilia o entendimento e direciona o tratamento das afecções da superfície ocular, pois permite a análise do grau de metaplasia escamosa, contagem do número de células caliciformes em casos de olho seco, hipovitaminose A, deficiência límbica corneal (síndrome de Stevens-Johnson, penfigóide ocular, queimaduras) (3) ; utiliza-se como método de análise microbiológica (viral) (4)(5) e na avaliação da superfície ocular em pacientes usuários de lente de contato (6) , em bebês prematuros (7) , e em pacientes diabéticos (8) .…”

Vitamin A and preterm infants: what we know, what we don't know, and what we need to know

“…44 Pooled data show a non-significant trend towards a reduction in ROP in vitamin A supplemented infants. 12 The pathogenesis of ROP is complex and includes free radical mediated oxidative damage to the developing retina which could in theory be ameliorated by the antioxidant properties of vitamin A.…”

“…43 Microscopic conjunctival changes consistent with vitamin A deficiency have been noted in preterm babies, but the relation to vitamin A status was not explored. 44 The preterm infant retina at birth contains several times less rhodopsin than at term birth 45 ; how rapidly rhodopsin is subsequently accreted, and how this is related to total body stores of vitamin A, is not known. The rhodopsin content of the developing rat retina is dependent on vitamin A sufficiency and is reduced by early exposure to light.…”

“…The long term consequences, if any, are unknown. Conjunctival impression cytology has been used to assess vitamin A status in adults 79 and can be easily incorporated into ROP screening 44 ; its relation to vitamin A status in the preterm infant has, however, not yet been fully explored.…”