Retinal scarring and abnormal growth of the blood vessels into the retina of the eye. The retina is the layer of cells in the back of the eye. Think of it asthe photographic film of the mind. Images captured on the retina are sent to the brain for processing. The retina does not mature until close to term (40 weeks gestation). The blood supply grows into the retina from the optic nerve, during the second trimester. The optic nerve is near the center of the retina. The blood vessels grow out from the center to the edges of the eye, but they do not completely reach the far sides of the eye until close to term.
When babies are born very premature, the normal growth of blood vessels into the retina is altered. Instead of the normal, orderly growth of the blood vessels into the retina, a distinctline forms beyond which the blood vessels seem unable to pass at first. As the process progresses, blood vessels begin growing in an abnormal process that can eventually damage the retina and other structures in the eye. These abnormally growing vessels can eventually lead to disruption of the retina and loss of eye function.
Fortunately, severe ROP is unusual and mostly found in extremely premature infants. Routine exams for ROP will be given to premature infants at risk starting at about the 5th or 6th week after birth. If severe ROP does develop, there are treatments that can reduce or prevent the loss of vision.