Doctor works for early diagnosis of ROP to prevent blindness in preemies
Samuel and Henry Bowen were born at 23 weeks and weighed less than two pounds each.
Their parents had never heard of ROP before the twins were diagnosed with it.
It’s a blinding eye disorder that the National Eye Institute says affects as many as 16 thousand preemies in the U.S. every year.
For example, Stevie Wonder was born six weeks too early and went blind.
Now, OHSU’s Dr. Michael Chiang is leading the charge for early screening and treatment of ROP.
“There are so many things that could potentially happen in the beginning especially for babies that early that eyesight and blindness wasn’t even something that we’d thought about yet,” said Dr. Chiang. “The blood vessels have number one, gotten thicker, and they’ve gotten really tortuous, meaning wiggly.”
At 34 weeks, Henry had aggressive ROP in his eye. Untreated, it could detach the retina and blind him.
Instead of using traditional laser or cryotherapy, Dr. Chiang injected Henry’s eyes with Avastin.
“In the course of a week, it basically reversed itself,” said Dr. Chiang. “If you diagnose it early enough that you can treat it, prevent a baby from going blind for their entire lifetime. We’ve got to make that diagnosis correct. We’ve got to make it on time.”
Dr. Chiang is trying to eliminate two obstacles to early diagnosis: accessibility to experts and a lack of standardized tests.
He’s creating a telemedicine solution.
“They would take a picture, send it to us and we could look at it,” said Dr. Chiang, “We could have our computer systems that we’re developing analyze those images and try to make a better diagnosis.”
The Bowens are grateful for their boys’ early diagnosis.
Samuel’s eyes improved on their own, and Henry’s checkups have been good.
“He’s still not out of the woods yet,” said Michael Bowen, the boys’ father, “But from where it was before to where it is now is a big difference.”
BACKGROUND: Retinopathy of prematurity (ROP) is a potentially blinding eye disorder that primarily affects premature infants weighing about 2 pounds or less. This disorder usually develops in both eyes and is one of the most common causes of vision loss in childhood. It can lead to lifelong vision impairment and blindness. ROP occurs when abnormal blood vessels grow and spread throughout the retina, which is the tissue that lines the back of the eye. These abnormal blood vessels are fragile and can leak, scarring the retina and pulling it out of position. This causes a retinal detachment. Retinal detachment is the main cause of vision impairment and blindness in ROP. With today’s advances in neonatal care, smaller and more premature infants are being saved. Not all babies who are premature develop ROP. There are approximately 3.9 million infants born in the U.S. each year and as many as 16,000 of these infants are affected by ROP. The disease improves on its own and leaves no permanent damage in milder cases. About 90 percent of all infants with ROP are in the milder category and do not need treatment, and about 400–600 infants each year become legally blind from ROP.
CAUSES AND TREATMENTS: There are several factors responsible for the development of ROP. The eye starts to develop at about 16 weeks of pregnancy, when the blood vessels of the retina begin to form at the optic nerve in the back of the eye. Blood vessels grow gradually toward the edges of the developing retina, supplying oxygen and nutrients. When a baby is born full-term, the retinal blood vessel growth is mostly complete. But if a baby is born prematurely, normal vessel growth may stop. Scientists believe that the periphery of the retina then sends out signals to other areas of the retina for nourishment. As a result, new abnormal vessels begin to grow. These new blood vessels are fragile and weak and can bleed, leading to retinal scarring. The most effective treatments for ROP are laser therapy and cryotherapy. Laser therapy “burns away” the periphery of the retina, which has no normal blood vessels. With cryotherapy, physicians use an instrument that generates freezing temperatures to briefly touch spots on the surface of the eye that overlie the periphery of the retina. Both laser treatments and cryotherapy are performed only on infants with advanced ROP. Both treatments are considered invasive surgeries and doctors don’t know the long-term side effects of each.
CURRENT STUDIES: Without less expensive and more accessible treatments, ROP will continue to condemn too many infants to a life of severe visual impairment or blindness. ROP is traditionally treated using laser ablation of the abnormal blood vessels, but advancements have been made using vascular endothelial growth factor (VEGF) inhibitors. Helen A. Mintz-Hittner, MD, Department of Ophthalmology and Visual Science, University of Texas Health Science Center, McGovern Medical School in Houston, has developed a unique and sometimes controversial treatment using bevacizumab that has changed the way many physicians treat advanced ROP. The treatment shows promise, however, delayed recurrence of ROP after bevacizumab treatments does sometimes occur, but usually only 5-10 percent. Dr. Mintz-Hittner emphasizes "the need for proper timing, careful technique, and appropriate long-term follow-up for outcomes" to properly manage an ROP infant.