New Study Does Not Support Use of Myo-Inositol to Prevent Blindness in Premature Infants

In a new study, investigators have found that a supplement used to prevent blindness from a rare eye condition—retinopathy of prematurity—which affect some preterm infants may be ineffective, and may even reduce their rates of survival.

Each year in the United States approximately 28,000 preterm infants are born before 31 weeks of gestation and weighing 2.75 pounds or less. Of these infants, 14,000 to 16,000 experience retinopathy of prematurity, an eye disorder caused by the growth and spread of abnormal blood vessels throughout the retina which can potentially lead to vision loss or lifeline vision impairment. Although 9 out of 10 infants with retinopathy of prematurity have a mild form of the condition that resolves without medical treatment, about 1,100 to 1,500 infants have the severe form of retinopathy of prematurity requiring treatment, and 400 to 600 infants with retinopathy of prematurity become legally blind.

Past research has found that premature infants with respiratory distress syndrome given breastmilk supplemented with inositol saw increased survival along with decreased incidence of ROP. In addition, another study found that premature infants with higher serum inositol concentrations at birth had a statistically significant lower incidence of severe retinopathy of prematurity.

Now in a new multi-institutional study published in the Journal of the American Medical Association, investigators found that contrary to previous findings, supplementation with myo-inositol—an experimental drug not approved for use in babies—in premature infants did not reduce the risk of Type 1 retinopathy of prematurity or death in premature infants.

Investigators enrolled 638 of 1760 planned participants who were born at a mean gestational age of 26 weeks. Of these infants, 317 received a 40-mg/kg dose of myo-inositol every 12 hours, initially intravenously, and then enterally when feeding, while 321 infants received a placebo for up to 10 weeks.

After discovering tiny glass particles in less than 2% of the vials in 1 of 2 batches of myo-inositol—caused by a process called delamination in which glass sheds tiny flakes—the investigators were forced to suspend the study, although the US Food and Drug Administration has found no evidence that these particles cause any harm and the study investigators found no differences in outcomes between infants given myo-inositol from batch 1 or batch 2.

In an analysis of their findings, the team found that 29% of the infants who received myo-inositol had either died or developed early-stage retinopathy of prematurity, compared with 21% of the placebo group.

In an interview with Rare Disease Report®, Rosemary Higgins, MD, from the National Institutes of Health’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) said that the study’s findings do not support use of myo-inositol in premature babies, and that the early stop of the trial limits definitive conclusions.

“We are not aware of a prevention for retinopathy of prematurity other than to prevent prematurity,” Dr. Higgins said. “There are approved treatments, including laser therapy, for established retinopathy of prematurity.”

The National Eye Institute (NEI) is currently supporting studies exploring new strategies to identify babies at greater risk of developing severe retinopathy of prematurity, especially those in underserved or remote areas, along with other studies on retinopathy of prematurity treatment.

The study was conducted by researchers in the Neonatal Research Network, a network funded by the NICHD, the NEI, and National Center for Advancing Translational Sciences.