Retinopathy of Prematurity (ROP)

What is retinopathy of prematurity?

Retinopathy of prematurity (ROP) is a condition in premature babies where abnormal blood vessels grow in the retina of the eye. The retina is the inside lining of the eye. It receives light and turns it into visual messages that are sent to the brain. If you compare the eye to a camera, the retina is like the film. The blood vessels that go to the retina are some of the last parts of the eye to mature. They have just completed growing when a full-term baby is born. This means that a premature baby’s retina is not completely developed at birth. The blood vessels in the immature part of the retina may develop abnormally in some premature infants. These blood vessels can become so abnormal that they cause damage to the eyes. They can even cause blindness.


What causes ROP?

The 2 biggest risk factors for developing ROP are:

  • low birth weight
  • low gestational age (the number of weeks a baby has been inside the mother’s uterus)

In premature babies, normal blood vessel growth factors, such as vascular endothelial growth factor (VEGF), can become elevated inside the developing eyes and the blood vessels in the eye cannot properly respond.


How is ROP diagnosed?

Premature infants born at or before 30 weeks gestational age and/or weigh less than or equal to 1,500 grams at birth are at risk for ROP. Less than 10 percent of premature infants at risk for developing ROP will require treatment.

Examinations generally begin in the neonatal intensive care unit at 4 or so weeks after birth. Eye examinations continue until the risk for ROP has passed or until the ROP becomes severe enough to put the infant’s vison at risk and trigger treatment. Some neonatal intensive care units use a system of telemedicine to take photographs of the infant’s retinas which are viewed by an eye specialist remotely.


How is ROP treated?

There are two primary treatment options.

Laser treatment - Laser treatment is applied to the portions of the retina that have not developed a blood supply. The laser treatment creates small burns to the retina which destroys the parts of the retina that produce VEGF, which causes ROP.

Injection of anti-VEGF agents - Medicine is injected into the eye to block VEGF activity. 


Are the treatments effective?

Most infants who undergo treatment with either laser or injection of anti-VEGF agents will maintain their vision.