What Is Retinopathy of Prematurity (ROP)?
Retinopathy of Prematurity (ROP) is a disease of the retina affecting prematurely born babies. In neonates in whom retinal vascularization is incomplete, resulting in abnormal proliferation of developing retinal blood vessels due to lack of oxygen.
The abnormal new blood vessels that grow are fragile and prone to leakage. This can result in significant damage to the retina including the formation of scar tissue and retinal detachment.
What Are the Different Types of Retinopathy of Prematurity?
Retinopathy of Prematurity is graded according to its severity: Stage I through "Plus" disease (+).
Stage 1: Demarcation line
Stage 2: Ridge
Stage 3: Ridge with extraretinal fibrovascular proliferation
Stage 4: Retinal detachment
"Plus" disease (+)
- Depending on severity, visual acuity varies from 20/20 to total blindness.
- Variable visual field defects, usually in the central field of vision (observed during an ophthalmological examination)
Diagnosis is made during an ophthalmological examination either before the infant leaves the hospital or within five to seven weeks of birth. Screening is recommended for all premature and low-birthweight babies, especially those receiving supplemental oxygen.
The main risk factor is premature birth. The condition is most common in infants with a birth weight of less than 1250 grams (~2.75 lbs) and a gestational age of less than 28 weeks.
ROP is commonly seen in low-birthweight infants, premature infants, and those who received oxygen therapy. It is occasionally seen in full-term neonates.
What You Can Do to Reduce Risk
The best way to reduce the risk of ROP is to prevent premature birth through prenatal care and educating expecting mothers about factors that can influence a baby's health in utero. If a child is born prematurely, close monitoring of oxygen levels and appearance of the retinal blood vessels is essential to prevent new blood vessel formation.
Many premature baby nurseries shield the baby's eyes with special sunglass filters that block the UV rays which have been implicated in the progression of ROP.
Currently, treatment relies on the destruction of the areas of the retina that do not contain any blood vessels and therefore are oxygen deprived. This becomes necessary only if the disease has reached a certain, well defined stage, as the milder forms often regress spontaneously. By destroying the oxygen deprived areas of the retina, the stimulus for the growth of the abnormal blood vessels is removed. The destruction is achieved by cryotherapy (literally freezing the retina, using a small pulse) or photocoagulation with laser energy. Rarely, surgery is undertaken in an attempt to remove the scar tissue.
To prevent ROP, pediatricians attempt, with close monitoring of the retina, to balance the amount of supplemental oxygen the infant is receiving with the appearance of the blood vessels. Oxygen is necessary, but too much can be damaging.