Retinopathy of Prematurity (ROP) is a serious eye disorder that primarily affects premature infants, especially those born before 31 weeks or under 1500 grams. ROP emerged as a leading cause of childhood blindness when increased survival of preterm infants revealed this new challenge after being widely recognized in the 1940s and 1950s as neonatal care improved.
The condition stems from incomplete development of retinal blood vessels, with risk heightened by factors such as low birth weight, oxygen therapy, and poor postnatal weight gain. Early ROP often shows no symptoms and is detected only through specialized eye exams in the NICU.
The disease progresses in five stages, from mild vessel changes to total retinal detachment. While early stages may resolve spontaneously, advanced ROP requires urgent treatment to prevent irreversible vision loss. Laser photocoagulation remains the gold standard for managing threshold disease, with anti-VEGF injections and surgery reserved for more complex cases. When treated in time, these interventions preserve central vision in the majority of cases.
This article provides a comprehensive overview of ROP, including its causes, symptoms, staging, diagnostic protocols, treatment options, prognosis, and preventive strategies. The role of NICU protocols, routine retinal screening, and interdisciplinary coordination in mitigating the severity of ROP is also emphasized. Supplementary information addresses the prevalence, consequences of untreated disease, and trusted centres for care, empowering caregivers with clarity on what to expect and how to act swiftly when ROP is diagnosed.
What is Retinopathy of Prematurity?
Retinopathy of Prematurity (ROP) is a potentially blinding eye disorder that affects premature infants, especially those born before 31 weeks of gestation or weighing less than 1500 grams.
ROP results from abnormal development of the retinal blood vessels, which begin to grow before birth but do not complete their formation until the last few weeks of pregnancy.
In early born babies, the retinal blood vessels are still immature and vulnerable. These vessels sometimes stop growing or grow abnormally, leading to areas where the retina does not receive enough oxygen or nutrients. In response, the body tries to compensate by producing new blood vessels, but these new vessels are often fragile and prone to leaking or bleeding.
The abnormal growth and leakage from these vessels threaten the delicate structure of the retina, which is responsible for capturing visual images. If left unchecked, this process has the potential to cause scarring, retinal detachment, and ultimately, vision loss. The earlier a baby is born and the lower the birth weight, the greater the risk for developing this condition.
ROP became more widely recognized in the 1940s and 1950s when advances in neonatal care led to greater survival rates for preterm infants, but also brought new challenges, such as ROP. Modern neonatal care now routinely includes screening and monitoring for ROP in high-risk infants, allowing for earlier detection and intervention.
What Causes Retinopathy of Prematurity?
Retinopathy of Prematurity is caused by incomplete blood vessel growth in the eyes of premature infants, with several contributing risk factors influencing its development. The eyes and retina of a full-term baby complete their blood vessel growth in the womb, but in premature babies, this process remains unfinished.
The most significant cause is the interruption of normal development due to early birth. Once outside the womb, the retina is exposed to a different oxygen environment, which disrupts its natural growth signals. Oxygen therapy in neonatal intensive care units (NICUs) is another major contributing factor. While supplemental oxygen is life-saving for preemies with underdeveloped lungs, if not carefully monitored, it disrupts normal retinal vascular growth and triggers abnormal vessel formation.
Low birth weight, specifically babies weighing less than 1500 grams, faces heightened risk because smaller infants are more likely to be born before their eyes are fully developed. The more premature and underweight the baby, the higher the risk for severe ROP. Additional risk factors include anemia, where the baby has fewer red blood cells to carry oxygen, and sepsis, a serious infection that stresses the body and impacts vessel growth.
Poor postnatal weight gain in the first few weeks of life also correlates with a greater likelihood of developing ROP. Infants who struggle with feeding, infection, or other medical complications after birth are more prone to abnormal blood vessel growth in the retina.
What are the Symptoms of ROP?
The symptoms of Retinopathy of Prematurity often do not appear in the early stages, and detection relies on specialized eye exams rather than visible signs.
In its initial phases, ROP progresses silently, with no discomfort or obvious changes in the baby’s appearance.
This absence of early symptoms is why routine screening in at-risk infants is so important. Pediatric ophthalmologists use advanced tools to examine the retina and detect abnormal blood vessel growth before it progresses to more severe stages.
As ROP advances, certain symptoms become more noticeable. Abnormal eye movements, such as wandering or jerking eyes (nystagmus), sometimes develop if the condition affects the retina significantly. Parents or caregivers might also observe leukocoria, which is a white reflection in the pupil, particularly noticeable in certain lighting or in photographs.
Crossed eyes (strabismus) can be another sign, especially when the baby’s visual development is disrupted by ROP. In the most severe cases, vision problems become evident as the child grows, including poor visual tracking or a lack of response to visual stimuli.
Retinal detachment, one of the most serious consequences of advanced ROP, presents with more dramatic symptoms. These include a noticeable white pupil, persistent abnormal eye movements, or, later in childhood, signs of poor vision or blindness.
Since early ROP is asymptomatic, timely and regular eye examinations in the NICU are critical for all at-risk infants. Detecting the disease before symptoms arise allows for early intervention, which significantly improves the chances of preserving vision.
What are the Stages of ROP?
Retinopathy of Prematurity is classified into five stages based on the severity of abnormal blood vessel growth and its effects on the retina. This staging system helps doctors determine the urgency of treatment and predict the likely outcome.
Stage 1 describes mild abnormal blood vessel growth, where only a slight deviation from normal development is visible. In most cases, this stage resolves without intervention as the baby grows and the vessels mature naturally.
Stage 2 indicates moderate abnormal growth, with more pronounced but still limited changes in the retinal vessels. Like stage 1, many infants recover fully with careful monitoring, though the risk of progression is slightly higher.
Stage 3 is characterized by severe abnormal vessel growth, where fragile new vessels start to proliferate and extend into areas of the retina where they do not belong. At this point, there is a real risk of complications such as leakage, bleeding, or the formation of scar tissue. This stage is particularly concerning because it is the threshold where urgent treatment becomes necessary to prevent further damage.
Stage 4 involves partial retinal detachment, which occurs when scar tissue pulls the retina away from the back of the eye. This detachment compromises visual function and, without prompt intervention, progresses to more severe visual impairment.
Stage 5 is the most advanced, involving complete retinal detachment. At this point, the retina is entirely separated from its underlying tissue, resulting in a high risk for permanent vision loss or blindness.
How is ROP Diagnosed?
ROP is diagnosed through routine screening of at-risk premature infants using specialized eye examinations performed by a pediatric ophthalmologist.
In the NICU, all infants born before a certain gestational age or with very low birth weight are enrolled in a screening protocol to ensure early detection.
The timing of the first screening is critical. Most guidelines recommend that the initial exam take place 4 to 6 weeks after birth or based on the infant’s gestational age at delivery. This ensures the retina has had sufficient time to develop, allowing for the identification of any abnormalities that may be present.
During the exam, ophthalmologists use indirect ophthalmoscopy, a method that provides a wide view of the retina and allows for detailed assessment of blood vessel growth. Retinal imaging, including digital photography or newer imaging technologies, supplements clinical examination and helps document changes over time.
Infants with abnormal findings are scheduled for frequent follow-up exams to track disease progression or resolution. Early identification of advancing stages allows for timely intervention, which is vital in preventing irreversible damage.
Is Retinopathy of Prematurity Curable?
Whether Retinopathy of Prematurity is curable depends largely on the stage at which it is diagnosed and the timeliness of intervention.
Infants diagnosed and managed in the early phases have a high recovery rate, as the abnormal vessels often regress naturally and the retina completes its development. Regular follow-up exams ensure that any progression is detected early, allowing for intervention to be initiated only if necessary.
In severe stages, treatment becomes more complex. Laser therapy or injections of anti-VEGF medications are used to stop abnormal vessel growth, and in cases where retinal detachment occurs, surgery is required to try to reattach the retina. Although these treatments help preserve as much vision as possible, complete restoration of normal vision is not always achievable.
Some children who experience advanced ROP need ongoing vision support after acute treatment. Glasses, vision therapy, and early intervention programs help optimize their visual development and quality of life. Parents and caregivers play a key role in supporting these efforts and ensuring regular follow-up.
How is Retinopathy of Prematurity Treated?
Treatment for Retinopathy of Prematurity depends on the severity and stage of the disease, ranging from careful monitoring in mild cases to advanced surgical interventions for severe forms. Each approach is tailored to the infant’s condition, with the main goal being the preservation of vision and prevention of further retinal damage. Below is a brief description of each:
1. Monitoring for Mild Cases
Monitoring is the primary approach for mild cases of ROP, as most early-stage disease resolves naturally without intervention. Premature infants with stage 1 or stage 2 ROP often experience spontaneous regression as the retina continues to develop and blood vessels mature in the weeks following birth.
Regular follow-up eye exams are essential, typically scheduled every 1-2 weeks, to ensure the disease does not progress to more severe stages. During these exams, a pediatric ophthalmologist examines the retina for any signs of advancing abnormal vessel growth or complications.
Most infants monitored for mild ROP develop normal vision with no long-term effects, provided the disease does not worsen. The reassurance of close observation allows families to avoid unnecessary treatment while ensuring any changes are detected early.
2. Laser Therapy
Laser therapy is the gold standard for treating severe ROP, particularly when abnormal blood vessel growth threatens to cause retinal detachment. In this procedure, a laser is used to treat the peripheral retina where abnormal vessels are forming, destroying the tissue to prevent further growth and reduce the risk of bleeding or scarring.
Laser treatment is performed under anesthesia to keep the infant comfortable and still. The procedure takes place in a hospital or specialized eye centre, often requiring only a single session, though some infants need additional treatments.
After laser therapy, follow-up care is critical as some children experience mild complications such as transient swelling or inflammation. In the long term, the treated eye is monitored for late-onset effects, including subtle changes in peripheral vision or refractive errors.
3. Anti-VEGF Injections
Anti-VEGF injections are an advanced treatment option for certain aggressive forms of ROP, particularly in Zone 1 disease or rapidly progressing cases. These injections involve administering medication directly into the eye to block vascular endothelial growth factor (VEGF), the protein responsible for abnormal vessel development.
The procedure is performed with meticulous care under sterile conditions, using a very fine needle to deliver the drug to the vitreous cavity. The medication inhibits new vessel growth and encourages the regression of existing abnormal vessels, reducing the risk of retinal detachment.
Anti-VEGF therapy is often chosen when laser treatment is less effective or poses higher risks, such as in very small infants or when the disease is close to the centre of vision.
Infants treated with anti-VEGF require long-term follow-up, as there is a risk of recurrence and unknown long-term effects on the developing eye. Despite these concerns, anti-VEGF injections have shown excellent results in halting disease progression and preserving central vision.
4. Vitrectomy or Surgery
Vitrectomy and other surgical interventions are reserved for advanced ROP where the retina has begun to detach or where standard therapies have failed. Vitrectomy involves removing the gel-like vitreous inside the eye and replacing it with a clear solution, allowing the retina to reattach and reducing traction from scar tissue.
Other procedures, such as scleral buckling, involve placing a flexible band around the eye to support the retina and encourage it to remain in place. These surgeries are complex and require a highly skilled pediatric retinal surgeon, typically performed in specialized centres.
Surgical treatment is often the last resort, as outcomes are less predictable and there is a risk of only partial vision recovery. Still, in selected cases, surgery prevents total blindness and stabilizes the eye’s structure, giving the child the best possible chance at retaining some sight.
Postoperative care includes intensive monitoring and visual rehabilitation, as well as support for families managing the challenges of low vision. The evolution of surgical techniques continues to improve results, offering hope even in the most difficult situations.
What’s the Success Rate of Laser Therapy for ROP?
The success rate of laser therapy for ROP is high, with studies showing effective prevention of blindness in over 85-90% of treated cases.
Laser photocoagulation, the standard of care for threshold or severe ROP, has transformed the prognosis for affected infants by targeting the abnormal peripheral retina before detachment occurs.
This intervention became widely adopted in the 1990s after clinical trials demonstrated its superiority over earlier treatments like cryotherapy. Laser therapy acts by ablating the areas of the retina that are not receiving normal blood vessels, stopping the signal for abnormal vessel growth and stabilizing the healthy portion of the retina.
Most infants who receive timely laser therapy retain good central vision, even if some peripheral vision is sacrificed. Preservation of the macula, the central area of the retina responsible for sharp vision, allows children to develop reading vision and function well in daily life. The overall impact on quality of life is significant, as blindness or severe visual impairment is avoided in the vast majority of cases.
Complications from laser therapy are relatively rare but include mild swelling, transient inflammation, or, in rare cases, damage to the central retina if the laser is misapplied. In the long run, children might experience refractive errors such as nearsightedness or subtle reductions in peripheral vision. However, these outcomes are far preferable to the risk of blindness from untreated ROP.
The success of laser therapy also depends on early detection and the skill of the treating ophthalmologist. Delayed treatment or incomplete laser coverage increases the risk of progression, so prompt referral and experienced care are vital.
Where to Visit for ROP Treatment?
Retinopathy of prematurity (ROP) requires prompt evaluation and specialized care at advanced ophthalmology centres equipped to manage neonatal retinal disorders. Ideal facilities for ROP treatment should have neonatal screening protocols, pediatric retinal specialists, and access to technologies such as indirect ophthalmoscopy, laser photocoagulation systems, and intravitreal injection capabilities.
Tertiary eye hospitals with dedicated pediatric ophthalmology and retina units are best suited for managing ROP across all stages. These institutions offer multidisciplinary collaboration between neonatologists and ophthalmologists, ensuring timely diagnosis, treatment, and follow-up in accordance with international ROP guidelines.
In India, Eye7 Eye Hospitals in Delhi provide structured ROP screening and treatment services as part of their pediatric retinal care program. With access to retinal lasers, anti-VEGF therapies, and surgical intervention when necessary, the hospital’s retina specialists manage both threshold and advanced ROP cases using evidence-based protocols.
Parents should prioritize centres with experience in neonatal care, routine screening programs for preterm infants, and long-term visual rehabilitation support. Early referral and continuous monitoring are essential, as timely intervention can prevent retinal detachment and permanent visual impairment in at-risk infants.
What Happens if ROP is Not Treated?
Untreated Retinopathy of Prematurity leads to progressive and often irreversible vision loss, with a high risk of permanent blindness.
The disease begins silently, but as abnormal blood vessels continue to grow unchecked, they invade the retina and create scar tissue. This scar tissue contracts over time, pulling the delicate retina away from the back of the eye in a process known as retinal detachment.
Once detachment occurs, recovery of vision becomes extremely difficult, even with surgery. Advanced retinal detachment almost always results in profound visual impairment or total blindness.
Untreated ROP also causes other long-term eye problems. Children with a history of severe ROP are at greater risk for developing strabismus (crossed eyes) and amblyopia (lazy eye), both of which interfere with normal visual development. Glaucoma, a serious condition characterized by increased pressure inside the eye, is more likely to develop in eyes damaged by ROP, potentially leading to further vision loss if not properly managed.
In the absence of treatment, abnormal vessels sometimes bleed into the eye, causing a vitreous hemorrhage that blocks light from reaching the retina and accelerates visual decline. Scar tissue and inflammation contribute to a cascade of eye changes, making later interventions less effective.
Children who lose vision from untreated ROP face significant challenges in their cognitive, social, and physical development. Early blindness limits opportunities for learning and independence, placing additional emotional and financial strain on families.
Can Retinopathy of Prematurity be Prevented?
Retinopathy of Prematurity (ROP) cannot be entirely prevented, but its risk can be significantly reduced through targeted neonatal care and prevention of premature birth.
The most effective strategy is prolonging pregnancy to allow full retinal vascular development.
For preterm infants, prevention focuses on careful management in the neonatal intensive care unit (NICU). Strict control of oxygen levels is essential, as excessive oxygen is a major risk factor for abnormal retinal vessel growth. NICUs use advanced monitoring systems and protocols to maintain oxygen within safe ranges that support both retinal and lung development.
Additional preventive measures include optimizing nutrition, preventing infections, and ensuring close coordination between neonatologists and ophthalmologists. These interventions lower the likelihood of severe ROP requiring treatment.
Education for parents about the importance of follow-up and home care further reduces risks.
How Common is ROP in Premature Babies?
ROP is a common complication among premature babies, affecting nearly 50% of those born weighing less than 1250 grams, though most cases are mild and do not threaten vision. The risk increases as birth weight and gestational age decrease, making extremely low birth weight and very premature infants the most vulnerable.
Advances in neonatal care have improved the survival of preterm infants, which has resulted in more babies being at risk for ROP. However, rigorous screening and treatment protocols have, at the same time, reduced the incidence of severe cases. Out of all infants diagnosed, only about 5-10% develop the vision-threatening form of ROP that requires intervention.
The majority of affected infants experience spontaneous regression of the disease as their retinas mature outside the womb. Regular eye exams ensure that those with mild ROP are closely monitored, catching any progression before complications arise. Families are reassured that most cases resolve without long-term consequences.
For the small proportion of infants who develop severe ROP, prompt diagnosis and treatment with laser therapy or anti-VEGF injections prevent blindness in most cases. Ongoing improvements in neonatal practice continue to lower the rates of severe ROP, especially in high-quality NICUs with experienced teams.
Resources
- https://pmc.ncbi.nlm.nih.gov/articles/PMC11890260/
- https://www.childrenshospital.org/conditions/retinopathy-prematurity-rop