Strategy Confirmed to Help Doctors Determine When to Treat Retinopathy of Prematurity
Scientists have shown that through an eye exam, doctors can identify infants who are most likely to benefit from early treatment for a potentially blinding eye condition called retinopathy of prematurity (ROP), resulting in better vision for many children. These long-term results of the Early Treatment for Retinopathy of Prematurity (ETROP) study confirm that the visual benefit of early treatment for selected infants continues through six years of age.
Akinso: Scientists have shown in a recent study, that through an eye exam, doctors can identify infants who are most likely to benefit from early treatment for a potentially blinding eye condition.
Brooks: The subject of this study was a condition called retinopathy of prematurity.
Akinso: Dr. Brian Brooks is the chief of the National Eye Institute’s Unit on Pediatric, Developmental and Genetic Ophthalmology. He explains retinopathy of prematurity, or ROP usually develops in both eyes, and is one of the most common causes of vision loss in children.
Brooks: By definition, it affects babies that are born prematurely and is caused by a change from the baby's environment from being in utero to outside the womb. Normally, during the last weeks of gestation, the blood vessels in the back of the eye called the retina are continuing to grow and mature. When an infant is born prematurely the change in that infant's environment sometimes results in differences in changes that are abnormal in how the blood vessels are forming.
Akinso: An estimated 15,000 premature infants born each year in the United States are affected by some degree of ROP. At-risk infants generally are born before 31 weeks of the mother's pregnancy and weigh 2.75 pounds or less. Dr. Brooks says about 90 percent of infants with ROP have a mild form that does not require treatment, but those who have a more severe form can develop lifelong visual impairment, and possibly blindness.
Brooks: The Early Treatment of Retinopathy of Prematurity or ETROP study was designed to look at the question—can we identify those infants who are going to go on to develop severe retinopathy of prematurity and if we treat those infants early do we do a better job at preventing blindness.
Akinso: In 2003, the ETROP study found that early treatment improved the vision and retinal health of certain infants after nine months.
Brooks: Both the initial study and now this follow up study have confirmed that in a subset of the infants who are beginning to develop retinopathy of prematurity, but have not hit what we classically call threshold…there is a subset called type 1 infants, that did significantly benefit from treatment. Whereas if the blood vessels appeared a different way, called type 2, those babies could be just carefully monitored for the time being.
Akinso: During pregnancy, the blood vessels of the eye gradually grow to supply oxygen and essential nutrients to the light-sensitive retina. If a baby is born prematurely, growth of the blood vessels may stop before they reach the edge of the retina. In these newborns, abnormal, fragile blood vessels and retinal tissue may develop at the edges of the normal tissue. The abnormal vessels can bleed, resulting in scars that pull on the retina. The main cause of visual impairment and blindness in ROP is retinal detachment. According to Dr. Brooks, additional research is needed to identify still better methods for the prevention and treatment of severe ROP. For more information on the results of this study and eye health research, visit www.nei.nih.gov. This is Wally Akinso at the National Institutes of Health, Bethesda Maryland.
About This Audio Report
Reporter: Wally Akinso
Sound Bite: Dr. Brian Brooks
Topic: Retinopathy of Prematurity, blindness