Correlation Between Hyperbilirubinemia and Retinopathy of Prematurity in Preterm Infants of Very Low Birth Weight and Less Than 32 Weeks Gestational Age: a Retrospective Study

Retinopathy of prematurity (ROP) is a disease related to prematurity with a multifactorial and only partially known etiopathogenesis.

A better understanding of its risk factors and potential protective factors may lead to the development of better preventive and therapeutic strategies in the future and, thus, ultimately, reduce the incidence of this pathology.

The starting hypothesis of our study is based on the proven physiological antioxidant effect of bilirubin, demonstrated by various in vitro and in vivo studies: it was hypothesized that bilirubin, by its antioxidant action, could exercise a protective role against oxidative stress pathologies typical of prematurity, including ROP.

However, the antioxidant action of bilirubin in humans, particularly newborns, is still controversial. Some studies have demonstrated a role protective of bilirubin against oxidative damage in preterm infants, while others have conversely observed that hyperbilirubinemia is a risk factor for ROP.

It has been hypothesized that bilirubin exerts its antioxidant effect only under conditions of increased oxidative stress, i.e., when the remaining antioxidant mechanisms are no longer sufficient to cope with the production of highly reactive molecules, for example, under conditions of hypoxia and hyperoxia.