Some premature infants need to have their eyes examined while still in the hospital to screen for retinopathy of prematurity.
This is a potentially blinding disease caused by abnormal development of retinal blood vessels in premature infants. It is mostly seen in low birth weight, pre term infants, that can result in progressive destructive changes in the developing “retina” of the newborn eyes. Abnormal blood vessels grow in stages in the retina causing leakage and scarring. When ROP is severe, it can cause the retina to pull away or detach from the wall of the eye and possibly cause blindness. Timely intervention with a laser and or retinal surgery is sometimes necessary to save sight.
There are typically two options once it is determined that a child has reached Type I ROP.
Most babies with ROP see normally for their age. It is only when ROP progresses to the most severe stages that vision is threatened. Fortunately, most ROP resolves without vision loss. The trouble is, no one can predict which babies will do well and which will develop problems. Effective screening and timely treatment (when indicated – see below) are the most important factors in preventing ROP-associated vision loss.
There are approximately 3.9 million infants born in the U.S. each year. About 14,000 are affected by ROP and 90% of those affected have only mild disease. About 1,100- 1,500 develop disease severe enough to require medical treatment and 400-600 infants each year in the U.S. become legally blind from ROP.
Birth weight and gestational age are the most important risk factors for development of severe ROP. Other factors that are associated with the presence of ROP include anemia, poor weight gain, blood transfusion, respiratory distress, breathing difficulties and the overall health of the infant. There is active research into the correlation of levels of growth factors in the blood and ROP. Close monitoring has decreased the impact of oxygen use as a risk factor for development of ROP. Light levels do not affect severity of ROP.
Ophthalmologists (Eye MD’s) who are skilled in the evaluation of infant eyes make the diagnosis of ROP. They examine the eyes after the pupils are dilated with drops. There is active research evaluating the effectiveness of digital photography for diagnosing ROP. Infants less than 1500 grams (3.3 lbs) and with a gestational age less than 31 weeks undergo eye examinations to monitor for ROP. Other infants who are deemed high risk by the neonatologist might also be screened.
ROP is described by its location in the eye (the zone), by the severity of the disease (the stage) and by the appearance of the retinal vessels (plus disease). The first stage of ROP is a demarcation line that separates normal from premature retina. Stage 2 is a ridge which has height and width. Stage 3 is the growth of fragile new abnormal blood vessels. As ROP progresses the blood vessels may engorge and become tortuous (plus disease).
When ROP reaches a certain level of severity, called type 1, the potential for retinal detachment (and possible permanent vision loss) becomes great enough to warrant consideration of eye surgery.
It is VERY IMPORTANT to have eye exams after discharge from the hospital since ROP may not be resolved before discharge. The timing of these exams is critical because delays in treatment can increase the risk of vision loss. Also, even with successful treatment of ROP, prematurity may lead to other vision abnormalities. Prematurity is a risk factor for the development of amblyopia (lazy eye), eye misalignment (strabismus), the need for glasses (even at a young age), and cortical visual impairment. Therefore, every premature infant needs the long-term attention of an ophthalmologist (Eye MD).