Babies who are born early (premature) are at risk for retinopathy of prematurity, or ROP. This is a problem that can affect eyesight. ROP is the growth of abnormal blood vessels on the lining of the back of the eye (retina). In severe cases, the blood vessels can detach the retina from the back of the eye.

The blood vessels on the retina don't finish growing until late in pregnancy. When a baby is born early, these blood vessels aren't yet fully developed. So the blood vessels complete their growth after the baby is born. Factors outside of the womb may cause them to grow abnormally. One problem may be changing levels of oxygen in the blood. ROP is more likely in younger or smaller preemies.

All premature babies in the NICU (neonatal intensive care unit) have their blood oxygen levels closely watched. Babies born at or before 30 weeks or weighing 1,500 grams or less (3 pounds, 5 ounces or less) are examined by an eye doctor. Eye exams can also be done by a trained member of the care team using a special camera to look at the back of the eye.

Some babies who weigh between 1,500 and 2,000 grams (3 pounds, 5 ounces to 4 pounds, 6.5 ounces) and have other health problems may need to have an eye exam because they are also at higher risk for ROP.

During eye exams, drops are used to expand (dilate) the pupil of the eye. This lets the doctor look through the pupil to check the blood vessels on the retina. If the doctor sees abnormal blood vessels, the ROP is rated from stage 1 (mild) to stage 5 (severe). The location of the blood vessels is also noted.

The first exam may be done around 4 to 6 weeks after birth or 31 weeks' gestational age, whichever is later. Based on the results of this exam and your baby's gestational age, your baby will need follow-up exams on a schedule set by your baby's eye doctor.

Mild ROP (stages 1 and 2) often needs no treatment. Babies with moderate to severe ROP may need treatment. Treatment usually depends on how severe the disease is. The doctor will talk to you about which treatment is right for your baby. Treatment options include:

• Laser photocoagulation. This uses a beam of light (laser) to treat the outer part of the retina and stop the extra blood vessels from growing. Babies often need general anesthesia for this treatment, so they will be asleep.
• Antivascular endothelial growth factor (anti-VEGF) therapy. The doctor injects anti-VEGF medicine into the inside of the eye (the vitreous), near the retina at the back of the eye. This stops abnormal blood vessels from growing and pulling on the retina. Numbing drops are used, and most babies do not need general anesthesia.

Sometimes ROP pulls the retina away from the back of the eye. This is called retinal detachment. Surgery can be done to try to put the retina back in place. This can help keep as much vision as possible. But sometimes there is too much damage for surgery to completely fix it. If this happens, your baby may not see well from that eye.

Many babies with ROP have no lasting effects. The more severe the disease, the higher the chance of permanent vision problems. Sometimes moderate to severe ROP can result in long-term visual problems. ROP can lead to blindness in rare cases.

Most babies will need follow-up eye exams. Babies with ROP are at increased risk for other eye disorders. These include myopia, strabismus, and astigmatism. Your baby may need glasses or other treatments.