Retinopathy of prematurity: Some epidemiological and paediatric aspects.

With the development of modern neonatal intensive care and the increase in the survival of very low birthweight babies, it was reported from a number of centres around the world that the incidence of retinopathy of prematurity (ROP) seemed to be once again on the increase. Since there was very little information regarding this condition in the United Kingdom after the early 1950s, a grant was awarded by the Medical Research Council in 1985 to enable further investigation. This thesis presents some of the results of this prospective survey of ROP. The epidemiological part of the study showed that in the geographically-defined population which we studied, acute ROP is common, being seen in 49.1% of infants weighing 1700 gm or less at birth. Most of these developed at worst, stage 1 or 2 disease (44.9%) and in all these 277 babies there was complete resolution. Of the 21 infants who developed more severe disease (stage 3 or 4), five (nine eyes) progressed to the cicatricial stages. However none of these infants was blind. There was no sex difference found but it was observed that there was a significant relationship between the stage of ROP and the race of the infant, Asian infants being found to have a greater tendency to develop stage 3 or 4 d disease. In the paediatric factors part of the study, several variables describing neonatal events and treatments were subjected to univariate analysis to find those which could be used in a multivariate analysis. Only a few of these variables are considered and discussed here. A significant association was found between the stage of acute ROP and cranial ultrasound findings of haemorrhage and periventricular leucomalacia, the presence of a persistent ductus arteriosus, a longer duration of assisted ventilation and oxygen treatment, bradycardias, apnoeas, cyanotic episodes and blood transfusions. Some of the difficulties in such a study are described.