When a Baby Is Born Too Soon, the Eyes Pay a Price
Picture a baby born at just 24 weeks — nearly four months early. Nearly every organ is still developing. The lungs need support. The brain needs protection. And the eyes? They face a particular danger that most people have never heard of.
That danger is called retinopathy of prematurity — and it can steal a child's sight before they ever see the world clearly.
A Condition That Affects the Tiniest Patients
Retinopathy of prematurity, or ROP, happens when abnormal blood vessels grow in the developing retina (the light-sensing layer at the back of the eye). In severe cases, those vessels pull the retina away from the eye wall — a retinal detachment that can cause permanent blindness.
ROP is one of the leading causes of childhood blindness worldwide. The more premature the baby, the higher the risk. Babies born before 28 weeks are especially vulnerable.
Why a Growth Factor Seemed Promising
Before birth, a hormone called insulin-like growth factor 1 (IGF-1) plays a key role in helping blood vessels in the eye develop properly. Think of IGF-1 as a traffic director — it tells the blood vessels where to go and how fast to grow.
When a baby is born too early, IGF-1 levels drop sharply. Without that signal, blood vessel development goes haywire. Researchers wondered: what if we could give premature babies IGF-1 to replace what they're missing and keep their eye vessels on the right track?
What the Studies Actually Tested
A Cochrane review — one of the most rigorous types of medical evidence summaries — analyzed two randomized controlled trials (studies where patients are randomly assigned to a treatment or a comparison group). Together, those trials enrolled 140 extremely premature infants born between 23 and 28 weeks of pregnancy.
Starting on the first day of life, infants received either intravenous IGF-1 (directly into a vein) or standard care, and were followed until they reached the equivalent of 40 weeks of pregnancy.
What They Found — and Didn't Find
The honest answer? Researchers couldn't tell.
The results showed no clear difference between IGF-1 and standard care for preventing ROP of any severity. The treatment didn't clearly reduce the worst form of ROP — the kind that requires intervention — and it didn't clearly prevent any ROP at all.
This doesn't mean IGF-1 is useless — it means the studies were too small to give a reliable answer.
There was also a concerning signal. In one of the larger trials, babies who received IGF-1 appeared to experience more serious adverse events (unexpected medical complications) than those who didn't. This isn't definitive, but it's not something that can be ignored.
That's Not the Full Story
The evidence from both studies was rated as "very low certainty" — the lowest level on the standard evidence scale used in medicine. That rating reflects two problems: the studies were small, and both had significant flaws in how they were designed. Both were also funded by the company that makes the IGF-1 product, which can introduce bias even in well-intentioned research.
In short, we simply don't know enough yet.
If you have a premature baby in the neonatal intensive care unit (NICU), IGF-1 is not a standard treatment for ROP at this time. Current standard care includes regular eye exams by a specialist, and if ROP progresses, treatments like laser therapy or anti-VEGF injections (medications that slow abnormal blood vessel growth) are available.
Talk to your NICU team if you have concerns about your baby's eye health. They will monitor your baby closely throughout their hospital stay.
Limitations to Keep in Mind
The main limitation here is the small number of babies studied — just 140 across two trials. This is far too few to detect small but meaningful differences in outcomes, especially for a serious condition like ROP. The trials were also conducted in well-resourced hospital settings in Europe and North America, so results may not apply in lower-resource environments.
Larger, better-designed trials are needed before IGF-1 can be recommended — or ruled out — as a treatment for ROP. Researchers and clinicians will be watching future studies closely. The idea behind IGF-1 therapy is still biologically sound, but sound ideas need rigorous proof before they can be offered to the most fragile patients. That proof doesn't yet exist.