Retinopathy of prematurity (ROP) is a potentially blinding eye disease. It affects premature infants who have abnormal blood vessel development in the retina, which is the light-sensitive area of the eye where images focus.
ROP mostly strikes preemies who weigh 2¾ pounds (1250 grams) or less, and who are born before 31 weeks of gestation, or about 7 to 11 weeks before the normal gestation period. The disorder usually develops in both eyes, and is among the most common causes of childhood vision loss. Although most cases of ROP resolve on their own, about 1 in 10 are severe enough to require medical intervention to prevent blindness.
Having a child born prematurely means grappling with a host of of concerns about the state of your child’s current health and their future development. Fortunately, with the right care from a qualified pediatric ophthalmologist, you can rest assured that your child has an outstanding chance at a lifetime of healthy eyesight.
ROP by the Numbers
According to the National Eye Institute, about 15,000 infants are born in the U.S. with ROP. Of those, about 10% – or 1,500 babies – have severe ROP. Approximately 3.6% of all cases – or about 500 U.S. infants – will be blinded by ROP each year.
15,000 Infants are born with ROP in the U.S. every year
When a baby is born preterm, he or she may grow fragile, weak blood vessels in the retina. These abnormal vessels can leak blood, leading to scarring along the optic tissues. When the scar tissue forms and then shrinks, it can stress the retina and pull it out of place. This can cause a serious condition known as retinal detachment. If not treated properly and quickly, retinal detachment can render a patient blind.
ROP Risk Factors
Besides birth weight and how premature a baby is, an infant may be at heightened risk for ROP if they have endured any of the following:
- Blood transfusions
- Difficulty breathing
- Respiratory distress or other respiratory complications
- Use of supplemental oxygen after birth
- Vitamin E deficiency
Besides posing the alarming risk of possible blindness, ROP is connected to vision irregularities later in life. An infant with ROP is more likely to develop certain eye problems as they grow, such as:
- Lazy eye (amblyopia)
- Crossed or misaligned eyes (strabismus)
- Retinal detachment
Shortly following birth, preterm babies should be screened for premature related illnesses, including ROP. A pediatric ophthalmologist may diagnose ROP during an examination in a hospital’s nursery or neonatal intensive care.
During the examination, the doctor will dilate your infant’s pupils with special drops. ROP may present at birth, or several weeks later. As such, premature infants at risk for ROP should have eyes examinations by an eye specialist a few weeks after being born. In particular, infants born at less than 3.3 pounds (1500 grams) and before 31 weeks should routinely receive eye exams to check for the onset of ROP.
If ROP is diagnosed, eye exams should continue regularly until the abnormal blood vessel growth resolves on its own or is adequately treated by the ophthalmologist.
If your baby is diagnosed with ROP, the doctor will use a set of standardizations to describe the disease’s location and severity. This serves as a guide to understand the extent of the disease and if treatment is needed.
The location of the disease is divided by zones centered around the optic nerve:
- Zone 1 is located in the back region of the retina, and is defined as the circle with a radius encompassing the optic nerve to twice the distance to the macula.
- Zone 2 includes the inner border of zone 1 and the outer border that is the distance from the optic nerve to the nasal ora serrata.
- Zone 3 is from the temporal crescent of the retina anterior to zone 2.
ROP has 5 stages of increasing progression:
- Stage I — This stage is characterized by mild abnormal blood vessel growth and a demarcation line that separates the normal vascularization (blood vessels) of the retina from the abnormal. Children with stage I often improve on their own without treatment and go on to enjoy normal vision.
- Stage II — Children with stage II will have moderately abnormal blood vessel growth and a ridge will have risen up from the line marking normal from abnormal vascularization in the retina. Like stage I, stage II can mean the patient improves without medical therapy and develops healthy vision.
- Stage III — In this stage, the abnormal vessels extend, growing towards the center of the eye, rather than along the surface of the retina as is normal. Infants with stage III may not need treatment and have normal vision. However, if a child also has “plus disease,” whereby the retinal blood vessels have twisted and engorged, then therapy is often pursued to prevent retinal detachment.
- Stage IV — This stage involves partial retinal detachment as the scar tissue and abnormal vessels tug the retina out of position. Treatment is usually the only way to prevent complete retinal detachment and possible severe visual impairments.
- Stage V — The last stage is defined by complete retinal detachment. Without treatment, the infant is at risk of enduring serious visual problems and possibly legal blindness.
When abnormal blood vessels continue to grow and a child’s eyesight is in jeopardy, namely in stages III – V, your pediatric ophthalmologist will likely recommend treatment. The most effective and frequently performed treatments for ROP are laser treatment and cryotherapy, a freezing therapy.
In both treatments, a very specific part of the retina is targeted to halt and possibly reverse abnormal blood vessel growth. While the central, sharp vision is spared, the patient’s side vision can be affected. The laser treatment works by burning off the affected edges of the retina, while cryotherapy relies on a freezing instrument to eradicate the diseased portions of tissue.
A less popular and newer therapy involves injecting medication into the eye. This treatment can be performed by itself, or in combination with laser treatment. Injection therapy results have been encouraging, but additional research is needed to determine long term side effects and efficacy.
Your treatment course and its success will largely hinge on the knowledge and experience of your pediatric eye doctor. Choosing an ophthalmology practice with a long record of exceptional patient care is a significant first step in protecting your child’s sight and overall eye health.