Retinopathy of Prematurity is normally not seen in infants weighing more than 1500 grams or about three pounds five ounces. The normal blood vessels of the retina, which is the nerve tissue in the back of the eye, do not complete their growth until the end of a normal full term pregnancy. In premature infants, the blood vessels may stop growing when they are born. When the vessels resume their growth, it can be in an abnormal fashion which causes damage to the retina.
A screening examination schedule has been determined to aid in detecting ROP and prevent its progression when possible. Eye examinations are usually performed in the hospital nursery with the use of eye drops to dilate the pupils so that the retina can be visualized. If any ROP is found, follow-up evaluations are recommended over the following weeks at intervals determined by the stage of the disease. In most cases, the ROP will resolve spontaneously as the blood vessels complete their growth pattern. In some cases, the ROP reaches an advanced stage (threshold) for which treatment becomes necessary. This treatment is in the form of laser therapy to the retina. It has been shown that treatment at the threshold stage of ROP can decrease, though not always eliminate the chances of retinal damage and subsequent poor vision.