None — Retinopathy of Prematurity
A normal pregnancy lasts about 40 weeks. Premature (preterm) birth is the delivery of a baby at less than 37 weeks. According to the CDC, about one in eight babies born in the U.S. is premature. These babies are often not fully developed and are at risk for a number of problems after birth, like jaundice, breathing problems and an inability to feed.
Another important complication of prematurity is retinopathy of prematurity (ROP). This condition affects the retina, or image-capturing structure at the back of the eye, and can lead to blindness. Eye development in the fetus rapidly accelerates during the last 12 weeks of pregnancy. Blood vessels grow toward the retina to supply it with oxygen and nutrients. After birth, the blood vessels in the eye stop growing. In a full-term baby, eye development is nearly complete. But in babies who are born prematurely, blood vessels may not have yet reached the edges of the retina, limiting the amount of oxygen to the retina.
Scientists believe the low oxygen state in some eyes of premature babies causes the retina to send distress signals. This leads to the growth of abnormal blood vessels that are weak and fragile. The vessels may leak blood, causing scars to form on the retina. As those scars shrink, or contract, they pull on the retina, causing the tissue to separate from the back of the eye (retinal detachment). Without intervention, vision in the eye is lost.
According to the National Eye Institute, about 14,000 to 16,000 babies have some degree of ROP. 90 percent of babies have mild cases. Researchers estimate roughly 2,000 premature babies develop severe ROP. About 500 of them develop severe vision impairment or blindness. ROP is most common in babies born before 31 weeks of pregnancy.
Screening for ROP
Thomas Lee, M.D., Pediatric Ophthalmologist with The Vision Center at Childrens Hospital Los Angeles, says it's very important for babies who are born prematurely to have regular eye screenings, starting soon after birth, to detect signs of ROP. That's typically done using a head lamp and magnifying glass to look at the retina at the back of the eye. However, it can be very difficult to see early signs of retinal detachment because the retina is so thin. Lee compares the screening to looking down from a ten-story building and trying to read the license plates of the cars on the street.
He and his colleagues have recently looked at another technology for ROP screening, called hand-held spectral domain optical coherence tomography (SD-OCT). The hand-held SD-OCT is a digitally-based imaging system. It magnifies the images of the retina and stores the information on a computer. That enables doctors to study the images more closely and compare older images with newer ones (to see if there is any progression of abnormal blood vessel growth). The system uses a low intensity red laser as a light, so it's not as blinding or harsh to the eyes as the standard light on a headlamp. In addition, since the device is hand held, it can be taken directly to the infant's bedside.
If ROP is detected, doctors can use laser therapy or cryotherapy to destroy areas in the edge of the retina where abnormal blood vessels are located, stopping the growth of the vessels. However, the researchers estimate that even with early treatment, about nine percent of high-risk infants will still develop severe vision impairment or blindness. The hand-held SD-OCT is can help doctors detect early signs of retinal detachment and enable more infants to get sight-saving treatment.
For general information on retinopathy of prematurity (ROP):
The Internet Low Vision Society National Eye Institute ROPARD: The Association for Retinopathy of Prematurity and Related Diseases
WSOC
/cloudfront-us-east-1.images.arcpublishing.com/cmg/LH3JSJEF3VBLRJLJQESEAG34AM.png)
