What Percentage of ROP Cases Resolve Without Treatment?

For many parents, a diagnosis of retinopathy of prematurity (ROP) brings worry, but it is important to know that many early cases improve without intervention. Across broad groups of premature infants, studies have found that roughly 84% to 88% of babies with ROP will see the condition resolve without laser therapy, injections, or surgery ^[1][2]. Eye doctors call this natural improvement spontaneous regression.

However, no statistic can predict your individual baby’s outcome. The chances of ROP going away depend heavily on the specific characteristics of your baby’s eyes, and even mild cases require scheduled, strict monitoring.

How Doctors Determine Your Baby’s Risk

Your pediatric ophthalmologist does not just look at the “stage” of ROP to determine if it will go away. They evaluate several factors together to decide if the disease is likely to regress or if it requires urgent treatment (often called Type 1 ROP) ^[3][4].

• Stage: This describes the appearance of the abnormal blood vessel growth.
  • Stages 1 and 2 (Mild): In observational studies, most mild cases regress naturally. One specific study found that 100% of Stage 1 cases and about 95% of Stage 2 cases resolved without treatment ^[1].
  • Stage 3 (Moderate to Severe): The likelihood of spontaneous regression drops considerably at this stage (around 22% overall in one study) ^[1]. While some very specific, stable cases of Stage 3 that do not meet treatment criteria may persist past 40 weeks postmenstrual age (time since the start of pregnancy) and eventually resolve ^[5], this is never a reason to delay care. Any ROP that meets the criteria for treatment requires prompt action ^[6].
  • Stages 4 and 5: These stages indicate partial (Stage 4) or total (Stage 5) detachment of the retina. Stage 4 is divided into 4A (not involving the central vision area) and 4B (involving the center). These advanced stages require urgent evaluation by a retinal specialist for surgical treatment to protect vision ^[7][8].
• Zone: This describes where the ROP is located in the eye. Disease closer to the center of the retina (Zone I) is more serious and less likely to resolve on its own than disease at the outer edges (Zones II or III) ^[9].
• Plus Disease: This is a high-risk sign where the blood vessels become abnormally wide and twisted. Plus disease is a major warning sign that the ROP is severe and may require immediate, urgent treatment ^[1][6].

Factors That Make Treatment More Likely

• Gestational age and weight: Extremely premature babies (born before 28 weeks) or those with very low birth weights are more likely to require treatment. When their ROP does resolve naturally, the improvement process often takes longer ^[10].
• Aggressive Posterior ROP: This is a rare, fast-moving form of the disease that typically does not resolve on its own and requires prompt medical care ^[1].

What “Spontaneous Regression” Really Means

When ROP regresses spontaneously, it means the active, abnormal blood vessel growth has improved. However, regression does not guarantee perfect vision later in life ^[11]. Children who had ROP and prematurity are still at a higher risk for long-term eye conditions, such as needing glasses (refractive error), “lazy eye” (amblyopia), or misaligned eyes (strabismus). Your baby will still need routine vision follow-ups even after the immediate risk of ROP has passed.

Why Every Scheduled Exam Matters

Even if your baby has mild ROP with a high statistical chance of resolving naturally, attending every follow-up eye exam is critical.

ROP can worsen rapidly, and parents cannot see it by simply looking at their baby’s eyes—there are no outward symptoms or signs of distress ^[12]. Only a pediatric ophthalmologist can monitor the retina using specialized equipment to see if the disease is regressing or if it has reached a threshold that requires treatment to prevent vision loss ^[3].

The specialist will decide exactly when ROP screening can safely end based on defined medical criteria (such as the blood vessels being sufficiently grown or the baby reaching a certain age). If you miss an appointment due to transportation or discharge logistics, do not wait for the next routine visit or for symptoms to appear. Contact the eye care team or your NICU social worker promptly to reschedule, as timing is crucial to protecting your baby’s sight.