Retinopathy of Prematurity Most Severe in Neonates Born Earlier Than 25 Weeks

Infants with a gestational age (GA) younger than 25 weeks are at risk for more severe retinopathy of prematurity (ROP) than those with older GAs, according to findings published in the Journal of American Association for Pediatric Ophthalmology and Strabismus. If patients with GAs before 25 weeks do develop ROP, they require more extensive ophthalmic exams, the study shows.

Researchers conducted a retrospective study to identify how increasing survival of low GA infants affects ophthalmologic screening and treatment rates. The study involved comparing the examination and treatment rates of infants born earlier than 25 weeks and those born at GA of at least 25 weeks. Included patients met institutional ROP screening criteria and were admitted to 2 neonatal intensive care units (NICUs) between 2017 and 2020. The researchers analyzed GA, birth weight, number of ophthalmology examinations, worst stage of ROP, presence type 1 ROP, and comorbidities associated with ROP. 

The study found that the before 25 weeks group had a higher number of total exams (P <.001), higher average worst stage of ROP (P <.001), and higher rate of type 1 ROP (P <.001), as well as higher mortality (P <.001), compared to the 25 weeks or later group. The researchers’ analyses revealed that only GA was significantly associated with developing type 1 ROP. 

Since the data indicate more comorbidities and risk factors for infants born at fewer than 25 weeks gestational age, the researchers suggest that clinicians characterize these neonates as a separate group from those born at 25 weeks or more. Additionally, they emphasize that ROP providers be prepared to encounter a higher volume of these patients as survival rates are currently at their highest.

“Worldwide, the mortality rate for infants of extremely preterm neonates, especially those born at 25 weeks gestational age or fewer, has been decreasing,” the researchers report. “ROP providers should be aware of the increasing numbers of infants requiring screening and treatment as these younger infants survive.”

Study limitations include those associated with its retrospective nature, as well as small sample size and possible confounding due to variability in neonatal care and in the diagnosis of treatable ROP.