A study led by a CHOP neonatology expert showed that infants with severe retinopathy of prematurity (ROP) diagnosed and treated under modern protocols remain at risk of nonvisual disabilities, even if blindness can be averted in most children.
ROP is a disorder of the blood vessels of the retina, which are not completely developed until a baby reaches full term. A baby born prematurely may have growth of abnormal blood vessels, or damage and scarring of existing blood vessels in the retina. This can lead to retinal scarring or detachment from the back of the eye, resulting in vision loss.
Severe ROP is not a rare condition, and its incidence has been rising. It occurs in at least 10 percent of unselected and extremely preterm infants — those born at less than 29 out of 40 weeks of gestation. Moreover, it is a serious problem in middle-income countries where even moderately preterm babies are affected.
“It is therefore important to research the association between this neonatal complication and adverse long-term child development,” said Barbara Schmidt, MD, MSc, an attending neonatologist at Children’s Hospital of Philadelphia and also a professor of pediatrics and Kristine Sandberg Knisely Chair in Neonatology, Perelman School of Medicine at the University of Pennsylvania.
This exploratory analysis reported in the Journal of the American Medical Association used data from a cohort of very low-birth-weight infants involved in the Caffeine for Apnea of Prematurity trial. Study participants included 1,582 children born at 31 centers between 1999 and 2004 and followed up at age 5. Of the 95 children who had severe ROP, 12 were bilaterally blind at 5 years. The study found that motor impairment, cognitive impairment, and severe hearing loss were three to four times more common in children with severe ROP than those without severe ROP.
These findings remind clinicians and parents that while blindness often can be prevented by timely retinal therapy in the neonatal intensive care unit, severe ROP remains a predictor of functional disability. It reinforces the need for long-term visual and developmental follow-up for infants who are diagnosed with severe ROP.
Yet, it remains unclear why there is an association between the development of severe ROP and the presence of nonvisual disabilities.
“We can only speculate,” Dr. Schmidt said. “The retina has been called a ‘window to the brain;’ hence, severe damage to the developing retina in a very immature baby may also indicate damage to the developing brain.”
Future studies could examine whether the association that investigators observed between severe ROP and nonvisual disability represents a “cause and effect” relationship. Dr. Schmidt also suggested that more research on effective strategies in the neonatal intensive care unit to prevent severe ROP is needed.
Contributing authors to the JAMA study are from the University of Melbourne, Australia; University of Toronto, Canada; the University of British Columbia, Canada; and McMaster University, Canada.