Retinopathy of prematurity (ROP) is a potentially blinding disease caused by abnormal development of retina blood vessels in premature infants. The retina is the inner layer of the eye that receives light and turns it into visual messages that are sent to the brain. When a baby is born prematurely, the retinal blood vessels can grow abnormally. Most ROP resolves without causing damage to the retina. When ROP is severe, it can cause the retina to pull away or detach from the wall of the eye and possibly cause blindness Babies 1250 grams or less and are born before 31 weeks gestation are at highest risk.
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 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. 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.
The diagnosis of ROP is made by an ophthalmologist (Eye MD) who examines the eyes after the pupils are dilated with drops. Infants less than 1500 grams (3.3 lbs) and with a gestational age less than 30-32 weeks undergo eye examinations to monitor for ROP [See figure 1].
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 had height and width. Stage 3 is growth of fragile new abnormal blood vessels. As ROP progresses the blood vessels may engorge and become tortuous (plus disease) [See figures 2 and 3].
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 laser treatment. Eyes that develop this disease have type 1 ROP and are usually treated.
Typically laser ablation is applied to the immature portion of the retina via a headset [See figure 4].
The outcome of laser treatment is usually favorable with disappearance of the abnormal blood vessels and resolution of plus disease. Despite accurate diagnosis and timely laser treatment, the ROP sometimes continues to worsen and the retina pulls away from the back of the eye. Eyes with retinal detachment caused by ROP generally have apoor visual prognosis. Retinal detachment can be treated with vitrectomy and/or scleral buckling procedure. There is active research in the use of medications to retard the growth of the abnormal blood vessels. Despite optimal treatment, some eyes with ROP progress to permanent and severe vision loss.
It is VERY IMPORTANT to have eye exams after discharge from the hospital since ROP may not be resolved before discharge. Also, even with successful treatment of ROP, prematurity may lead to other vision abnormalities. Prematurity is a risk factor for the development ofamblyopia (lazy eye), eye misalignment (strabismus), and the need for glasses (even at a young age), and cortical visual impairment. Therefore, every premature infant needs the lifelong attention of an ophthalmologist (Eye MD).
National Eye Institute
VISIT SITE »
The Association for Retinopathy of Prematurity and Related Diseases (ROPARD)
VISIT SITE »
More technical information can be found on the EyeWiki Site.
Are you a medical professional, interested in joining AAPOS? Find out more here ▶