Retinopathy of Prematurity
Retinopathy of Prematurity also known as ROP most commonly affects premature infants (babies who are born before 31 weeks of gestation), which weigh less than 2.7 pounds or 1250 grams. A normal pregnancy has a gestation of 38-42 weeks.
The less the baby weighs, the more prone it is to ROP. Retinopathy of Prematurity is a potentially blinding disease that usually occurs in both eyes. This disease is among the most common reasons for blindness in childhood and in extreme cases, it can also lead to lifelong blindness and vision impairment.
Globally, 15 million babies (approx.) are born early and don’t complete the full weeks of gestations. While many premature babies are saved in today’s world due to advance technology and better neonatal care, the risk of ROP is still high in these infants. ROP does not occur in every baby. Occurring in a few premature infants, retinopathy of prematurity can improve in some cases and will leave no damage or side effects.
9 in 10 infants who are diagnosed with ROP are in the mild category and don’t need any treatment. However, a few of these cases which are in the severe category can get impaired vision or blindness.
About 1,100-1,500 infants are diagnosed with ROP each year globally.
Stages of ROP
There are five stages in ROP which range from mild to severe.
Stage I is a mild condition with a minor abnormality in the growth of blood vessels. Many babies who have Stage I ROP, improve with time and develop normal vision without any treatment.
Stage II is slightly higher than Stage I, but not serious. The blood vessel growth is moderately abnormal but the vision of children improves and eventually they get normal vision.
In Stage III, the abnormality in the growth of blood vessels is severe. Blood vessels increase in size, but their direction is towards the center of the eye instead of growing along the surface of the retina. Some babies who get stage III ROP, improve without getting any treatment and sometimes develop normal vision back.
In some cases, when babies have stage III ROP and simultaneously develop Plus Disease — enlargement of blood vessels in the retina worsens the disease. If treated in stage III, there is a good chance the ailment will be cured.
Stage IV is the phase when the retina is partially detached. The bleeding happens because of the traction from the scar that makes the abnormal vessels exert a force on the walls of the eye.
Stage V is quite similar to Stage IV. In stage IV the retina is completely detached. In the end-stage of the disease, the eye is left alone and the infant can develop extreme visual impairment issues and it can even lead to blindness.
ROP of Stage I and Stage II can be controlled in the early stages. However, sometimes it develops very rapidly. If left untreated, it can even destroy the vision.
Does ROP also cause other complications?
There is a higher risk of eye diseases in infants who are diagnosed with ROP. These eye problems include myopia (nearsightedness), glaucoma, retinal detachment, strabismus (crossed-eyes) and amblyopia (lazy eye). However, in most cases, these diseases can be treated very easily.
What causes ROP?
Infants develop retinopathy of prematurity when blood vessels grow abnormally and spread all over the retina — the tissue that is at the back of the eye. The abnormal blood vessels are weak and can leak which results in scarring the retina and disturbing its position. The main reason for visual impairment and blindness in ROP is retinal detachment.
Occurring of ROP is due to many different factors. The eye begins to develop in the sixteenth week of pregnancy and the blood vessels of the retina begin to form on the optic nerve at the back section of the eye. The blood vessels develop slowly towards the corners of the retina and supply nutrients and oxygen.
In the last twelve weeks of pregnancy, the eye grows rapidly. In premature infants, these vessels grow towards the edges of the retina which causes retinopathy. If the baby is born before completing these final stages, the risk of ROP would be high in the infants.