The ROP eye check your premature baby must not miss

Retinopathy of prematurity (ROP) is an eye disease of babies born early that can cause blindness if it is missed. It causes no outward signs, so the only way to find it is a timed eye examination. In India, most babies born at 34 weeks or less, or weighing 2000 g or less, need this check, usually by the fourth week of life.¹

What is retinopathy of prematurity?

ROP is abnormal growth of blood vessels in the retina, the light sensing layer at the back of the eye. In severe cases these vessels scar and pull the retina away, which leads to blindness.

The retina's blood vessels grow slowly from the centre outwards during pregnancy and finish around the due date. When a baby is born early, this growth is interrupted. Later, the unfinished retina sends out growth signals, and new vessels may grow in a wild, fragile way. Indian experts say ROP is one of the main causes of childhood blindness in India that could be prevented.²

Why do premature babies get ROP?

Being born early is the main cause. The risk goes up with poorly controlled oxygen, infection and slow weight gain after birth.¹

Oxygen matters a great deal. In a large trial, babies kept at lower oxygen levels had about half as much severe ROP as those kept higher, though more of them died.³ So NICUs aim for a careful middle range, not too high and not too low. Infection and poor growth also add to the risk.¹

Which babies need ROP screening in India?

Indian operational guidelines advise screening every baby in a newborn unit who was born at 34 weeks or less, or weighed 2000 g or less at birth.¹

Bigger or more mature babies also need screening if they had a sick course, such as breathing support, long oxygen treatment, sepsis, blood transfusion, brain bleeds, breathing pauses or poor weight gain. The baby's doctor can also ask for screening in any other premature baby.¹ If you are unsure whether your baby needs it, ask. Do not assume.

Why are India's ROP screening rules wider than in the UK or US?

Because in India, severe ROP is seen in bigger and more mature babies than in rich countries. Screening rules must match the babies who actually get the disease.

An international study found that babies with severe ROP in highly developed countries were born at about 25 weeks and weighed about 750 g on average. In less developed countries, they were born at up to 33.5 weeks and weighed up to about 1500 g. About 13 percent would have been missed by UK screening rules.⁴ The authors linked this to differences in the quality of newborn care.⁴

When should the first ROP eye test be done?

Indian guidelines say the first ROP examination should take place by 25 to 30 days of life. Babies due to go home earlier should be screened before discharge.¹

For the smallest and earliest babies, national guidance advises an earlier first check, at 2 to 3 weeks of age, to catch a fast moving form called aggressive ROP. One Indian unit found these very early checks rarely changed treatment and has asked for more research, so follow your own unit's plan.⁵ The timing depends on days since birth, not on discharge. If your baby goes home on day 14, the eye check still has to happen on time.

What happens if ROP screening is missed?

A missed check can mean permanent blindness. Most Indian children who reach the final stage of ROP were simply never screened.

At one tertiary eye hospital in north India, 115 babies arrived with stage 5 ROP (a fully detached retina) in both eyes over a year. Nearly 90 percent had never been screened, and over 90 percent of these eyes were blind for good.⁶ This is exactly what timely screening prevents.

Is the ROP eye test painful for my baby?

It is uncomfortable, and most babies cry, but it is brief. Simple comfort measures help a lot.

Drops are put in the eyes beforehand to widen the pupils. The eye doctor then holds the eyelids open with a small clip and looks at the retina with a special light, or takes pictures with a camera. Indian guidelines advise swaddling, a pacifier and a trained nurse watching the baby's heart rate and breathing.¹ Some tiny babies have feeding upset or extra breathing pauses for a few hours afterwards. One Indian unit saw this in about a third of very premature babies after early checks.⁵

What do zone, stage and plus disease mean on the ROP report?

Zone tells you where the disease is, stage tells you how severe it looks, and plus disease means the vessels at the back of the eye are swollen and twisted, a sign of active disease.

• Zone 1, 2 or 3: zone 1 is the centre and most worrying. Zone 3 is the outer edge.
• Stage 1 to 5: stage 1 is a faint line. Stage 5 is a fully detached retina.
• Plus disease: dilated, twisted vessels.
• Aggressive ROP: a fast form that can appear in bigger babies too, especially where resources are limited.

These terms come from the international classification, updated in 2021.⁷

Does every baby with ROP need treatment?

No. Most babies screened have no ROP or mild ROP that settles by itself as the vessels finish growing. Only a smaller group needs treatment.

A large American trial showed which eyes benefit from early treatment. Eyes with "type 1" ROP, such as any zone 1 disease with plus disease, should be treated. Eyes with milder "type 2" ROP can be watched closely and treated only if they get worse.⁸ Indian guidelines use these same criteria.¹

How quickly must ROP be treated?

Very quickly. Indian guidelines say treatment should be given within 48 hours of finding ROP that needs it.¹

ROP that needs treatment can get worse within days. Make sure you know exactly where to go and whom to call if your baby needs treatment, and keep all phone numbers handy. Delay at this point can cost your child's sight.

What is laser treatment for ROP?

Laser treatment uses light to seal the outer part of the retina that has no blood vessels. This switches off the signal driving the abnormal vessels.

Laser has been the standard treatment for many years, and Indian guidelines call it the gold standard.¹ It works well, but it permanently destroys the outer edge of the retina.⁹ It is done under sedation or anaesthesia, in the NICU or an eye hospital.

What are anti-VEGF injections for ROP?

Anti-VEGF medicines, such as bevacizumab or ranibizumab, are injected into the eye to block the growth signal. They act quickly and let the normal vessels keep growing.

In the BEAT-ROP trial, ROP came back less often after bevacizumab than after laser for zone 1 disease, but there was no clear difference for zone 2.⁹ In the RAINBOW trial, ranibizumab gave slightly better results than laser, though the difference was just short of statistical proof.¹⁰ ROP can come back weeks or months after injections, so these babies need longer follow-up.⁷

How many ROP eye checks will my baby need?

Usually several. Checks are repeated at the intervals the eye doctor sets, until the retina is fully grown or any ROP has settled.

Write down every date. Carry the discharge summary and the last eye report to each visit. Indian guidelines stress clear records of the findings and the next date before any discharge or transfer.¹

Can ROP be checked with a camera?

Yes. Trained technicians can take wide field pictures of the retina, and an eye specialist reads them, sometimes from another city.

The KIDROP programme in Karnataka has run screening this way since 2008 and helped bring ROP checks to district hospitals with few eye specialists.¹¹

Can ROP be prevented?

Partly. Good newborn care lowers the risk: careful oxygen use, preventing infection, breast milk feeding and good weight gain.¹

Steroid injections before an early delivery help indirectly by making breathing problems milder. Parents can help by making sure every doctor knows the baby needs screening and by never missing a date.

When should I call the eye doctor or paediatrician?

Call promptly in any of these situations.

• Your baby's ROP check date has passed and they have not been seen.
• Nobody has mentioned an eye check for your premature baby by the third week of life.
• You see a white glow in the pupil, in photos or in light.
• The eyes wander, or your baby does not seem to look at or follow faces as other babies do.
• One eye looks different from the other.