Understanding Retinopathy of Prematurity

What is Retinopathy of Prematurity?

Retinopathy of prematurity (ROP) is an eye disease that can occur in premature babies. ROP causes the growth of abnormal blood vessels in the newborn’s eye. Retinopathy of prematurity can lead to blindness.

ROP primarily affects infants who weigh 2¾ pounds or less at birth, according to the National Eye Institute, and who are born before 31 weeks of gestation. The smaller the infant is, the more likely he or she is to develop ROP.

Advances in medicine, particularly in neonatal care, doctors and nurses are able to save smaller and more premature babies than ever before. In fact, about 28,000 of the nearly 4 million babies born in the U.S. each year weigh 2 ¾ pounds or less. About 14,000 to 16,000 of these “premies” develop some degree of ROP.

Fortunately, about 90 percent of premature infants who develop ROP have a milder form of the disease and do not need treatment, as the condition clears up on its own and leaves no permanent damage. Those with a more severe form of the disease can develop impaired vision or even blindness. Each year, approximately 1200 to 1500 babies develop ROP severe enough to require treatment and about 400 to 600 infants will become legally blind from retinopathy of prematurity. It is important to note that not all premature infants develop retinopathy of prematurity.

“Jesse also uses his newfound independence to help others. At college, he uses a 3D printer to create artificial hands for children. The small parts can be tricky to both handle and see. It’s the kind of thing that once might have been closed off to him.” – Learn how Jesse learned to live with RoP by clicking here.


ROP affects the light-sensitive tissue that lines the back of the eye, known as the retina. Light carries visual information about the world. Light enters the eye and strikes the retina, which converts the information into electrical pulses. The optic nerve carries these pulses to the brain, which converts the pulses into a visual image.

A complex network of tiny blood vessels transport oxygen- and nutrient-rich blood to the retina, which it needs to function well. Retinopathy of prematurity can cause blood vessels to grow abnormally large and in random spots in the retina. The abnormal blood vessels can leak or bleed, which can scar the retina. The scars can shrink and pull on the retina, detaching it from the back of the eye. Because the retina is essential for sight, detaching it will cause blindness.

ROP also affects the pattern in which blood vessels grow in the retina. The eye starts to develop at about 16 weeks of pregnancy. Blood vessels near the optic nerve at the center of the retina develop first, and then gradually grow towards the edges of the retina. The eye develops rapidly in the last 12 weeks of pregnancy. When babies are born full-term, the growth of blood vessels in the retina is nearly complete. The blood vessels may not have reached the edges of the retina in premature babies, however, so those areas of light-sensitive tissue may not have received the oxygen- and nutrient-rich blood they needed to develop.

Scientists think that the edges of the retina, known as the periphery, in babies with ROP send out “signals” to other areas of the retina for nourishment. The body responds to these signals by building blood vessels, which tend to be abnormally weak and fragile. These abnormal blood vessels can leak and bleed, which can scar the retina.

ROP causes the growth of abnormal blood vessels in the newborn’s eye. eSight glasses for the visually impaired can help enhance sight.
ROP causes the growth of abnormal blood vessels in the newborn’s eye.

Signs and Symptoms

ROP typically develops in both eyes. It is one of the most common causes of visual loss among children. The disease can lead to lifelong vision impairment – in severe cases, retinopathy of prematurity can even lead to blindness.

Retinopathy of prematurity does not usually cause any signs or symptoms when it develops in a newborn. Only an eye care professional can diagnose ROP.

Infants with retinopathy of prematurity are at a higher risk for developing certain eye problems when they get older. Eye problems associated with ROP include retinal detachment, nearsightedness, glaucoma, strabismus or “crossed eyes,” and amblyopia or “lazy eye.” Eye care professionals can treat or control these complications of ROP.

Stages of Retinopathy of Prematurity

There are five stages of retinopathy of prematurity, ranging from mild (stage I) to severe (stage V):

Stage I — Characterized by mild growth of abnormal blood vessels that resolves on its own without further progression; many babies who develop stage I improve without treatment and eventually develop normal vision

Stage II — Moderately abnormal blood vessel growth that usually improves on its own and without treatment; many children with stage II ROP develop normal vision as they age

Stage III — Characterized by the growth of severely abnormal blood vessels; eye care professionals consider treatment to reduce the risk of retinal detachment in children who have stage III “plus disease,” which means the blood vessels are enlarged and twisted

Stage IV — Features a partially detached retina that occurs when bleeding and abnormal eyes tug at the retina until it pulls away from the wall of the eye

Stage V — The end stage of the disease when the retina detaches completely from the wall of the eye; left untreated, the infant can have severe visual impairment and potentially even blindness

Blonde little girl with white shirt who exhibits signs of amblyopia.
Close up portrait of adorable little girl living with with Amblyopia, a sign often associated with Retinopathy of Prematurity.

Support for Retinopathy of Prematurity

Children with mild ROP do not require treatment. Those with advanced forms of retinopathy of prematurity may benefit from treatment that stops the development of abnormal blood vessels and the complications they cause, such as scarring, tugging the retina away from the wall of the eye, and blindness.

Surgery stops the development of abnormal blood vessels by scarring the tissue enough that blood vessels cannot form there. Surgery focuses on scarring the periphery of the retina to spare central vision. Preserving the central retina in this way allows the eye to see straight ahead, distinguish color, read, and do other important tasks. Because it focuses on the peripheral retina, though, the patient may lose some amount of peripheral vision.

Laser surgery and injections are the most common types of surgery for moderate types of ROP. Other procedures, such as scleral buckling and vitrectomy, can help with an advanced case of ROP with a detached retina.

Many people with visual problems associated with retinopathy of prematurity benefit from using low vision aids. Vision loss and loss of visual acuity from retinopathy of prematurity respond well to the magnification offered by low vision aids, and they respond particularly well to advanced assistive eyewear technology. eSight is one type of advanced assistive eyewear technology that uses state-of-the-art cameras, smart algorithms and high resolution screens to create crystal clear, real-time images. These devices make seeing faces, reading, watching television or using a computer possible.

With the help of an eye care professional and low vision aids, children and adults with retinopathy of prematurity can enjoy better vision.

Did you find this post helpful? Learn more about Stargardt’s disease.

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