According to Two Researchers from NewYork-Presbyterian Hospital, the Findings Will Change How Physicians Treat Disease
Jan 5, 2004
Two physician-scientists from NewYork-Presbyterian Hospital were co-authors of a new study which demonstrates that earlier laser treatment for certain premature infants resulted in an overall better vision outcome. Results of the multi-center clinical trial, sponsored by the National Eye Institute (NEI), a part of the National Institutes of Health (NIH), and published in the December issue of the Archives of Ophthalmology, give physicians new, improved treatment options for Retinopathy of Prematurity (ROP), a blinding disease that affects premature, low-birth-weight infants and is a leading cause of vision loss in children.
This finding will change how physicians treat ROP, says Dr. John Flynn, A.S. Cohen Professor of Pediatric Ophthalmology at Columbia University College of Physicians Surgeons, and a co-investigator of the Early Treatment for Retinopathy of Prematurity (ETROP) study, and attending ophthalmologist at NewYork-Presbyterian Hospital/Columbia. It has already led to revised standards for identifying premature infants who are most likely to benefit from early treatment.
Premature, low-birth-weight infants face a host of medical complications with lifelong consequences. The results of this study allow us to improve treatment for ROP and, hopefully, the quality of life for children who most need sight-saving therapy, said Dr. Thomas Lee, study co-investigator, Assistant Professor of Ophthalmology at Weill Cornell Medical College, and Associate Director of the Robert M. Ellsworth Ophthalmologic Oncology Center at NewYork-Presbyterian Hospital/Weill Cornell Medical Center.
The results of the ETROP study, which was conducted at 26 participating centers in the U.S., demonstrate that premature infants, who are at the highest risk for developing vision loss from ROP, will retain better vision when therapy is administered in an early stage of the disease. This treatment approach was found to be better than waiting until the previously defined threshold for ROP treatment, defined as when the risk of retinal detachment approaches 50 percent. Just as importantly, the study also established the value of an improved risk assessment model to more accurately identify those infants who are at the highest risk for developing severe vision loss from ROP.
ROP is a disease that develops when abnormal blood vessels grow and spread throughout the retina. In most infants who develop it, the disease spontaneously subsides, permitting development of normal vision. But other infants progress to a severe form of ROP and are in danger of becoming permanently blind.
Current treatments for ROP involve laser therapy or cryotherapy to retard blood vessel growth. A consequence of these treatments, known clinically as blood vessel ablation, is a partial loss of peripheral vision. Nonetheless, treatment is valuable in preserving the most important part of sight the sharp, central vision needed to read, see faces or perform detailed tasks.
Although current therapy can stem ROP's progression, many infants are still blinded by the disease. Due to a lack of clinical criteria to predict which patients will ultimately develop severe vision loss from ROP, ophthalmologists were forced previously to defer treatment until it was clearly indicated. Unfortunately, delaying therapy can leave infants who might benefit more from early treatment with poor visual outcomes.
As part of the ETROP study, a new computerized risk model, developed by NEI-supported researchers, was used to identify high-risk infants early in the disease. The risk model assessed birth weight, ethnicity, gestational age, ophthalmic exam findings, whether the baby was a single or multiple birth, and whether the infant had been born in a hospital that participated in the study. A birth weight of 2.75 pounds (1250 grams) has been shown to be a major risk factor for developing ROP.
Once identified, the infants were then assigned randomly either to treatment at the standard threshold (50 percent chance of retinal detachment) or to early treatment. Researchers found that early treatment significantly reduced the likelihood of poor vision from 19.5 to 14.5 percent at about one year of age. Early treatment also considerably reduced the likelihood of structural damage to the eye from 15.6 to 9.1 percent.
The study will continue to follow these infants until age six to ensure that the benefits of early treatment persist into childhood.
Each year ROP affects an estimated 14,000 to 16,000 premature, low-birth-weight infants in the United States and thousands more worldwide. Of these cases, approximately 1,500 infants will develop severe ROP that requires treatment. Despite available treatment, about 400 to 600 infants with ROP still become legally blind each year.