Retinopathy of Prematurity

Retinopathy of Prematurity (ROP) is a potentially sight-threatening condition that affects premature infants. ROP predominantly affects premature infants, particularly those born before 31 weeks of gestation or weighing less than 3.3 pounds (1500 grams) at birth. The prevalence of ROP varies depending on factors such as gestational age, birth weight, and access to specialized neonatal care. In developed countries, advances in neonatal intensive care have contributed to improved survival rates for premature infants but have also led to an increased incidence of ROP.

This condition arises when abnormal blood vessels form on the retina of each eye. The retina, located at the back of the eye, is crucial for vision. As these abnormal blood vessels and scar tissue develop over time, they can lead to various serious vision problems, including:

• Retinal damage and detachment, causing permanent and severe vision loss
• Crossed eyes (strabismus)
• Increased eye pressure (glaucoma)
• “Lazy eye” (amblyopia)
• Nearsightedness (myopia)

Causes of Retinopathy of Prematurity

1. Incomplete Retinal Vascularization: Premature birth interrupts the natural development of blood vessels in the retina, leading to abnormal growth.
2. Oxygen Therapy: High levels of oxygen used to support premature infants’ respiratory needs can contribute to the development of ROP.
3. Low Birth Weight: Infants born with low birth weight, particularly those weighing less than 3.3 pounds (1500 grams), are at higher risk for ROP.
4. Prematurity: The earlier the gestational age at birth, the higher the risk of developing ROP.

Symptoms of Retinopathy of Prematurity

Detecting retinopathy of prematurity (ROP) in babies isn’t straightforward since there are typically no noticeable signs or symptoms. Instead, diagnosis requires a close examination of the baby’s eyes, including the formation of blood vessels in their retinas, by an ophthalmologist.

Unlike many other conditions where symptoms are evident, ROP may quietly develop without any visible indications. Therefore, regular eye examinations by a qualified ophthalmologist are crucial for identifying ROP and determining the appropriate course of action. This close monitoring allows for timely intervention if necessary, helping to safeguard the baby’s vision and overall eye health.

Risk Factors

• Premature Birth: Infants born before 31 weeks of gestation are at higher risk for developing ROP.
• Low Birth Weight: Babies weighing less than 3.3 pounds (1500 grams) at birth are more likely to develop ROP.
• Prolonged Oxygen Therapy: Excessive oxygen exposure, especially during the first weeks of life, increases the risk of ROP.
• Intraventricular Hemorrhage (IVH): Premature infants who experience bleeding within the brain’s ventricles are at increased risk for ROP.

Prevalence of Retinopathy of Prematurity

In the United States, ROP affects approximately 14,000 to 16,000 infants each year. Among them, about 90% have a mild form that resolves on its own, while 1,100 to 1,500 require treatment for severe ROP. Sadly, ROP results in legal blindness for 400 to 600 infants annually.

Diagnosis of Retinopathy of Prematurity

Retinopathy of prematurity (ROP) diagnosis involves a series of steps overseen by neonatologists and ophthalmologists:

1. Identification of At-Risk Babies: Neonatologists assess babies who are at risk for ROP and refer them to ophthalmologists for further evaluation.
2. Eye Examination (Screening): During the examination, the ophthalmologist administers eye drops to dilate the baby’s eyes and carefully examines them for signs of ROP. They might also capture digital images of the baby’s retinas. This initial screening typically occurs four to six weeks after birth.
3. Screening Criteria: Different countries have varying guidelines for ROP screenings. In the U.S., infants are usually screened if they meet one of the following criteria:
   • Gestational age of 30 weeks or less.
   • Birth weight of 1,500 grams (3.3 pounds) or less.
   • Higher gestational age or birth weight but with other risk factors for ROP.

Follow-Up Screenings: Depending on the initial screening results and individual risk factors, babies may require additional screenings every one to three weeks. The ophthalmologist will determine when these screenings are no longer necessary, typically when the blood vessels in the baby’s retinas are fully developed, and there’s no risk of retinal detachment.

Staging of ROP

If ROP is diagnosed, the ophthalmologist uses a staging system to assess its severity:

Stages 1 and 2: Mild to moderate ROP that often resolves without treatment.

Stage 3: ROP that may require treatment to prevent retinal damage or detachment.

Stage 4: Severe ROP leading to partial retinal detachment, necessitating urgent treatment.

Stage 5: A most severe form of ROP resulting in total retinal detachment, requiring urgent treatment. Despite intervention, vision loss or blindness may still occur.

Additional Terminology:

Alongside the staging system, other terms healthcare officers may use are:

Aggressive retinopathy of prematurity: A rapidly worsening severe case of ROP.

Plus disease: Severe ROP characterized by widened and tortuous blood vessels in the retina.

Treatments for Retinopathy of Prematurity

For many babies, retinopathy of prematurity (ROP) improves without intervention. However, if the condition is severe and there’s a high risk of retinal detachment, treatment is necessary. Approximately 10% of babies screened for ROP require treatment.

Treatment options include:

1. Laser Surgery: This procedure involves using small laser beams to treat the sides of the retina, halting the growth of abnormal blood vessels. While effective, it may result in some loss of peripheral (side) vision.
2. Cryotherapy: Instead of using laser beams, freezing temperatures are utilized to prevent the spread of blood vessels on the retina. Although an older form of treatment, it also carries the risk of side vision loss.
3. Injection: A newer approach involves injecting an anti-cancer drug, such as Bevacizumab (Avastin), into each eye. This medication blocks the growth of new blood vessels. While promising, more research is needed to ascertain potential long-term side effects and the possibility of ROP recurrence.

In cases of retinal detachment, more complex surgeries may be required:

• Scleral Buckling: A small, elastic band is placed around the white part of the eye, causing slight compression. This action helps reposition the torn retina closer to the outer eye wall.
• Vitrectomy: During this procedure, the clear gel (vitreous) in the center of the eye is removed and replaced with saline solution. Additionally, scar tissue pulling the retina out of place is excised.

Surgery can often halt disease progression and prevent vision loss. However, up to 25% of babies who undergo ROP surgery may experience some degree of vision loss.

Due to the heightened risk of future eye problems, children with ROP should have annual follow-ups with their eye doctor until adulthood. This ongoing monitoring helps ensure early detection and management of any emerging issues.

Home Care Remedies and Prevention

While ROP treatments are primarily administered in a clinical setting, parents can support their child’s eye health by ensuring regular follow-up appointments with a pediatric ophthalmologist. Maintaining a healthy lifestyle during pregnancy, including adequate prenatal care and avoiding smoking, can reduce the risk of premature birth and subsequent complications such as ROP.

When to See a Doctor

Parents of premature infants should promptly seek medical attention if they notice any changes in their child’s vision or eye appearance, such as abnormal eye movements or persistent eye redness. Early detection and intervention are crucial for preventing vision loss associated with ROP.

Outlook/Prognosis

The prognosis for infants with ROP varies depending on the severity of the condition and the timeliness of intervention. With early detection and appropriate treatment, many infants with ROP can achieve favorable visual outcomes. However, severe cases of ROP may lead to permanent vision impairment or blindness if left untreated.

In conclusion, Retinopathy of Prematurity poses significant risks to the vision health of premature infants. Understanding the causes, symptoms, risk factors, diagnosis, treatments, prevention strategies, and prognosis of ROP is essential for optimizing patient outcomes and preserving vision in vulnerable newborns.

Sources

1. American Academy of Ophthalmology. (2021). Retinopathy of Prematurity.
2. Mayo Clinic. (2022). Retinopathy of Prematurity.
3. National Eye Institute. (2021). Retinopathy of Prematurity.
4. American Association for Pediatric Ophthalmology and Strabismus. (2020). Retinopathy of Prematurity (ROP).