Retinopathy of prematurity is strongly associated with premature birth Preterm (Premature) Newborns A preterm newborn is a baby delivered before 37 weeks of gestation. Depending on when they are born, preterm newborns have underdeveloped organs, which may not be ready to function outside of... read more , with most cases occurring in infants who are born before 30 weeks of development in the uterus.
In the most severe cases, the rapid abnormal growth of the small blood vessels can lead to detachment of the retina and loss of vision.
Because affected newborns have no symptoms, diagnosis depends on a careful examination by an eye specialist (ophthalmologist).
This disorder is usually mild and resolves without treatment, but the eyes need to be monitored by an ophthalmologist until blood vessel growth is mature.
If the disorder is severe, newborns require laser treatment or injections of bevacizumab.
The retina Structure and Function of the Eyes The structures and functions of the eyes are complex. Each eye constantly adjusts the amount of light it lets in, focuses on objects near and far, and produces continuous images that are instantly... read more is the transparent, light-sensitive structure at the back of the eye. The blood vessels in the retina start growing in a fetus at about 18 to 20 weeks of development in the uterus and continue growing until the fetus is full term. When infants are born very prematurely, the blood vessels supplying the retina may stop growing for a time. When growth resumes, it occurs in a disorganized fashion. During disorganized rapid growth, the small blood vessels may bleed. In the most severe cases, this process may ultimately result in detachment of the retina Detachment of the Retina Detachment of the retina is separation of the retina (the transparent, light-sensitive structure at the back of the eye) from the underlying layer to which it is attached. People notice a sudden... read more from the back of the eye and severe loss of vision.
Viewing the Retina
Premature infants are at increased risk of retinopathy of prematurity if they have serious disorders such as infections, bleeding in the brain Bleeding in and around the brain Birth injury is damage that occurs as a result of physical pressure during the birthing process, usually during transit through the birth canal. Many newborns have minor injuries during birth... read more , or lung disorders (such as bronchopulmonary dysplasia Bronchopulmonary Dysplasia (BPD) Bronchopulmonary dysplasia is a chronic lung disorder in newborns caused by extended use of a ventilator (a machine that helps air get in and out of the lungs) and/or extended need for supplemental... read more ). Premature infants who receive oxygen for a long time (for example, because their lungs are immature) are also at increased risk.
Diagnosis of Retinopathy of Prematurity
Retinopathy of prematurity does not cause symptoms, so diagnosis depends on careful examination The Eye Examination A person who has eye symptoms should be checked by a doctor. However, some eye disorders cause few or no symptoms in their early stages, so the eyes should be checked regularly (every 1 to 2... read more of the back of the eyes by an ophthalmologist (a medical doctor who specializes in the evaluation and treatment of all types of eye disorders). Routinely, therefore, an ophthalmologist examines the eyes of all premature newborns who weigh less than 3 pounds (about 1,500 grams) at birth or who were in the uterus for less then 30 weeks. Eye examinations are repeated every 1 to 3 weeks as needed, until growth of the blood vessels in the retina is complete.
Newborns with severe retinopathy must have eye examinations, at least yearly, for the rest of their life. If detected early, detachment of the retina can be treated with surgery in an attempt to avoid loss of vision in the affected eye.
Prognosis for Retinopathy of Prematurity
Retinopathy of prematurity is usually mild and resolves spontaneously. However, in a small percentage of affected infants weighing less than 2 pounds (about 1 kilogram) at birth, the disorder is severe and progresses to cause detachment of the retina and vision loss within 2 to 12 months after delivery.
Children whose retinopathy of prematurity has healed are at greater risk of developing other eye problems such as nearsightedness Causes In refractive disorders, light rays entering the eye are not focused on the retina, causing blurred vision. The shape of the eye or cornea or age-related stiffness of the lens may decrease the... read more (myopia), strabismus Strabismus Strabismus is an intermittent or constant misalignment of an eye so that its line of vision is not pointed at the same object as the other eye. If untreated, strabismus can cause amblyopia ... read more , and amblyopia Amblyopia Amblyopia, a common cause of vision loss in children, is a decrease in vision that occurs because the brain ignores the image received from an eye. Vision loss may be permanent if the disorder... read more . A few children with moderate, healed retinopathy of prematurity are left with scars on the retina and are at risk of detachment of the retina later in life. Rarely, glaucoma Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage (often, but not always, associated with increased eye pressure) that can lead to irreversible loss of vision... read more and cataracts Cataract A cataract is a clouding (opacity) of the lens of the eye that causes a progressive, painless loss of vision. Vision may be blurred, contrast may be lost, and halos may be visible around lights... read more can also occur.
Prevention of Retinopathy of Prematurity
When premature newborns need oxygen, oxygen levels are monitored carefully so that the lowest amount of oxygen necessary can be used. Oxygen levels can be indirectly monitored using a pulse oximeter Pulse oximetry Both arterial blood gas testing and pulse oximetry measure the amount of oxygen in the blood, which helps determine how well the lungs are functioning. Arterial blood gas tests are invasive... read more (an external sensor that measures the level of oxygen in the blood going through a finger or toe).
Treatment of Retinopathy of Prematurity
For very severe retinopathy of prematurity, laser photocoagulation treatment is done on the outermost portions of the retina. In this treatment, a laser beam is used to stop the abnormal growth of blood vessels and decrease the risk of detachment of the retina and loss of vision.
A drug called bevacizumab may also be injected to stop the abnormal growth of blood vessels in the retina.
If retinopathy of prematurity leads to a partial or complete detachment of the retina, sometimes surgery is done to reattach the retina and prevent further vision loss.
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Children's Eye Foundation of AAPOS: Practical information about prevention, detection, research, and education to protect the vision of children