As a mom of twin preemies, I always keep my eyes and ears open about health problems related to prematurity. Here’s the latest about retinopathy of prematurity (ROP).
ROP occurs in approximately 15,000 babies in the US each year, according to recent estimates. ROP is one of the most common causes of visual impairment in children.
But how does ROP occur? Medline Plus describes this condition:
The blood vessels of the retina begin to develop 3 months after conception and complete their development at the time of normal birth. If an infant is born very prematurely, eye development can be disrupted. The vessels may stop growing or grow abnormally from the retina into the normally clear gel that fills the back of the eye. The vessels are fragile and can leak, causing bleeding in the eye. Scar tissue may develop and pull the retina loose from the inner surface of the eye. In severe cases, this can result in vision loss.
In addition, preemies are usually treated with oxygen at birth. Excessive oxygen can stimulate the growth of blood vessel that can lead to ROP. Improved monitoring of oxygen supply has reduced ROPs caused this way. However, babies born before the 31st week of gestation and weighing less than 3 pounds are at high risk for ROP. However, all preemies should be screened for ROP.
Long-term results from the Early Treatment for Retinopathy of Prematurity (ETROP) show that ROP, when caught early, can reduce or prevent impairment. Screening entails an eye exam that examines the appearance and location of the blood vessels in the eyes. Through the examination, the severity of ROP can be determined.
ROP may be categorized into the following types based on the characteristics of the blood vessels:
- Type 1 ROP is characterized by lots of new blood vessels growing which may be dilated or twisted, with a very high risk for visual impairment
- Type 2 ROP is characterized by moderate amounts of growing blood vessels.
ROP treatment options include laser therapy or cryotherapy (using freezing temperatures) which stops or slows down the growth of blood vessels.
The ETROP study revealed that babies with Type 1 ROP benefits from early treatment but not those with Type 2 ROP. These findings, which were initially based on a short-term 9-month study, have been confirmed by a long-term study which followed up the patients for up to 6 years. 75% of those with Type 1 ROP cases treated early were spared progression to legal blindness compared to 67% of those who receive treatment at standard time. No difference in outcomes was observed in those with Type 2 ROP regardless of the timing of the treatment.
According to study leader William V. Good of Smith-Kettlewell Eye Research Institute in San Francisco:
“The long-term study has given clinicians evidence that infants with ROP should be treated with different strategies based on an infant’s risk for a severe form of the disease, which can be determined through an exam at the bedside.”