What's Retinopathy of Prematurity?
Having a child born prematurely means grappling with a host of concerns about the state of your child’s current health. With the right care from a qualified pediatric eye doctor, you can rest assured that your child has an outstanding chance at a lifetime of healthy eyesight.
Prematurity can be challenging for children and families alike. The eyes are particularly susceptible to problems immediately after birth and for the rest of your child’s life. Retinopathy of Prematurity (ROP) is a potentially blinding eye disease that affects premature infants who have abnormal blood vessel development in the retina, the light-sensitive area of the eye where images focus.
Causes of Retinopathy of Prematurity
Blood vessels in the eye start developing in utero and if a child is born before that process is complete, there will be a part of the retina that does not have blood flowing to it. Blood vessels swell and overgrow in the light-sensitive layer of nerves in the retina at the back of the eye. When the condition advances, the abnormal retinal vessels extend into the jellylike substance (vitreous) that fills the center of the eye. Bleeding from these vessels may scar the retina and stress its attachment to the back of the eye, which can cause partial or complete retinal detachment and potential blindness.
Who is at Risk for Retinopathy of Prematurity
ROP mostly strikes preemies who weigh 2¾ pounds (1250 grams) or less, those 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 need medical intervention to prevent blindness.
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
Once your child has cleared the 50-week postmenstrual date, their risk for retinopathy of prematurity is quite low. However, your child may still be at risk for other eye problems as they get older including high myopia, or nearsightedness, as well as retinal tears or detachments in later life.
Eye Screenings for Preterm Babies
During pregnancy, blood vessels grow from the center of a developing baby's retina 16 weeks into the mother's pregnancy. They then branch outward and reach the edges of the retina between 8 months into the pregnancy and full term. In babies born early, normal retinal vessel growth may be disrupted, and abnormal vessels can develop which can cause leaking and bleeding into the eye. ROP has no signs or symptoms when it first develops in a newborn and the only way to detect it is through an eye exam by an eye doctor.
Shortly following birth doctors screen preterm babies for premature related illnesses, including ROP. Examination by the pediatric ophthalmologist may take place in a hospital’s nursery or neonatal intensive care.
What to Expect During An Examination
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. 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.
Vigilant monitoring is the key to ensuring the optimal outcome for your child and if early signs of retinopathy of prematurity present, laser treatment can slow the process in most patients. Surgery can also help in severe cases. These have both helped to decrease your child’s chances of severe vision loss in later life. Our eye care specialists will discuss how often to follow your child which ensures that they detect any early changes of retinopathy of prematurity.
For low-risk infants, it’s recommended to follow up every 2 weeks until 50 weeks of postmenstrual age, or 10 weeks after the original due date. Higher risk infants would need more frequent follow-up, either weekly or twice weekly.
Besides posing the alarming risk of possible blindness, ROP relates to vision irregularities later in life. An infant with ROP is more likely to develop certain eye problems as they grow, such as:
Diagnosing & Staging ROP
ROP has 5 stages of increasing progression:
- Stage I — This stage shows mild abnormal blood vessel growth. 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. A ridge will have risen 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 legal blindness.
Importance of Early Treatment
If a doctor diagnoses your baby with ROP, they 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 in the back region of the retina and is 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.
Treatments for ROP
In stages III – V a child’s eyesight is in jeopardy when abnormal blood vessels continue to grow. Our pediatric ophthalmologists will likely recommend treatment at this point. The most effective and performed treatments for ROP are laser treatment and cryotherapy.
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. 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. Doctors can either perform this treatment can by itself, or in combination with laser treatment. Injection therapy results have been encouraging, but needs more research 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 eye health.
Contact SightMD today to schedule an appointment with one of our doctors to discuss your child's vision health at one of our convenient locations!