About Retinopathy of Prematurity (ROP)
Retinopathy of prematurity (ROP) is a disease that occurs in premature babies. It causes abnormal blood vessels to grow in the retina, the layer of nerve tissue in the eye that enables us to see. This growth can cause the retina to detach from the back of the eye, leading to blindness.
Some cases of ROP are mild and correct themselves, but others require treatment using laser or other means to stop the growth of the abnormal blood vessels, making sure they do not bleed or pull on the retina, so that vision loss or blindness is prevented.
Normal growth of blood vessels
Blood vessels grow from the center of a developing baby's retina 16 weeks into the mother's pregnancy, and then branch outward and reach the edges of the retina 8 months into the pregnancy and is complete only about two weeks after birth.
Causes of ROP
A premature baby has other risky diseases like a poorly functioning immature lung, bleeding within the brain tissues and jaundice. These infants are more likely to suffer from severe infections which also jeopardizes the normal growth of the blood vessels in the retina. Blood vessels then tend to grow abnormally and randomly in the eye causing Retinopathy of prematurity . These abnormal vessels tend to leak blood, formation of band like scar tissue which later pull and detach the retina.
Since the retina is a vital part of vision, its detachment will cause blindness. Once ROP develops, there are chances that it can stop or reverse itself at any point, so it often resolves as the baby grows. Sometimes, though, the disease may progress to cause scarring, which pulls the retina away from the rest of the eye.
Examination of the eye
ROP has no signs or symptoms. The only way to detect it is through an eye examination by an ophthalmologist through specialized equipment called Indirect Ophthalmoscope. The examinations have to be done in periodic schedules to closely observe the progressive growth of the vessels whether it is of normal or abnormal in nature and also to decide whether treatment is needed.
ROP treatment is used to stop the growth of abnormal blood vessels by focusing laser on the peripheral retina (the sides of the retina) to preserve the central retina (the most important part of the retina). When ROP progresses further to a stage of scarring ROP surgery involves removal of scar tissue on the peripheral retina and reattach the retinal layers.
Since surgery focuses treatment on the peripheral retina, these areas will be scarred and some amount of peripheral vision may be lost. However, by preserving the central retina, the eye will still be able to perform vital functions like seeing straight ahead, distinguishing colors, reading, etc.
The most frequently used methods of ROP treatment are:
- Laser Treatment, the most common type of ROP treatment, in which small laser beams are used to scar the peripheral retina (also called photocoagulation). This procedure lasts about 30-45 minutes for each eye. The laser beams are delivered through the same equipment, the indirect ophthalmoscope which is used for the examinations.
- Cryotherapy, where freezing temperatures are used to scar the peripheral retina to stop abnormal blood vessel growth. For many years, cryotherapy (also called cryosurgery) was the accepted method of ROP surgery, but it has been all but replaced by laser therapy.
- Intraocular Injections, are also tried nowadays when laser therapy cannot be administered due to rapidly developing severe form of disease or when severe bleeding has already occurred inside the eye. This can stop further bleeding so that laser can then be given after sometime.
- Retinal Surgery is done when the retina is already in a detached state. This is an extensive surgery requiring anaesthesia and chances of good visual recovery is usually remote.
Your baby's ophthalmologist will determine and discuss with you which ROP surgery method is best suited for the baby.