Medical Abbreviation: A Closer Look at Retinopathy of Pre-maturity

Retinopathy of pre-maturity is generally defined as abnormal blood vessel development in the retina of the eye of a premature infant. In utero, blood vessel development begins in the eye three months after conception but doesn’t complete until near the 40th week of the gestation period. Therefore, when premature birth occurs, this development is likely interrupted. Further, the earlier the premature birth the greater the disruption to this development.

The effects of this disruption can cause the vessels to stop growing completely or to grow abnormally. Those abnormal vessels are fragile and thus prone to leaking. This leaking can then cause bleeding in the eye and scarring of the retina, sometimes so severe that the retina is actually pulled out of place.

Being born prematurely does not automatically mean that an infant will develop ROP. Some reports have estimated that each year about 14,000-16,000 infants will be diagnosed with ROP in the United States in a mild form that leaves no permanent damage. Approximately 1,100-1,500 preemies will develop ROP to an extent that will lead to impaired vision or blindness. Four to six hundred infants will have such a severe form of ROP that they will become legally blind. ROP has five recognized stages of diagnosis;

• Stage I – Mild, often no treatment is needed, the disease resolves without need for intervention
• Stage II – Moderately abnormal blood vessel growth, most often this stage also resolves on its own without need for intervention
• Stage III – Severely abnormal blood vessel growth, some infants do not require intervention even at this stage. Those infants who are diagnosed with Stage III and “plus disease” do require treatment. The addition of “plus disease” with the staging diagnoses means that the blood vessels around the retina have become twisted and enlarged.
• Stage IV – Partially detached retina. Traction from the scar is noted, produced by bleeding. The abnormal vessels are pulling the retina away from the wall of the eye.
• Stage V – Completely detached retina of the eye. Treatment is required at this stage. If treatment does not occur, severe visual impairment and blindness are expected.

There are other risk factors besides pre-maturity that can lead to the development of ROP:

• Apnea
• Heart Disease
• High carbon dioxide in the blood
• Low blood acidity
• Low blood oxygen
• High PaO2 levels
• Respiratory Distress
• Bradycardia

If treatment is needed, it should start within 72 hours after diagnosis. If an infant is born at 27 weeks or later, their first eye exam should occur at 4 weeks of age. Those infants who are born less than 27 weeks should have exams by nine weeks of age. Treatment can include cryotherapy (freezing) to prevent the spread of abnormal blood vessels or laser therapy (photocoagulation). Laser therapy works by stopping the abnormal blood vessels from growing. If the retina detaches, then surgery is required.

Greene, A. Medical Encyclopedia: Retinopathy of Prematuirty (2007). Retrieved from www.nlm.nih.gov/medlineplus.

National Eye Institute. Retinopathy of Prematurity(ROP). (2008). Retrieved from www.nei.nih.gov/health/rop.