Retinopathy of prematurity

Alternative names

Retrolental fibroplasia; ROP

Definition

The retina is the part of the eye that transmits visual information to the brain. Retinopathy of prematurity is a disorder of retinal blood vessel development in the premature infant. The severe form is characterized by retinal vascular proliferation, scarring, retinal detachment, and Blindness.

Causes, incidence, and risk factors

The blood vessels of the retina begin to develop three months after conception and complete their development at the time of normal birth. When an infant is born very prematurely, the infant's eye development will be disrupted.

In infants who develop retinopathy of prematurity (ROP), the vessels grow abnormally from the retina into the normally clear gel that fills the back of the eye. Here, without support, the vessels are fragile and often hemorrhage into the eye.

This is followed by scar tissue development which pulls the retina loose from the inner surface of the eye and draws it toward the center of the globe, producing a retinal detachment. This can reduce vision or, if severe, result in complete Blindness.

Many premature infants develop transient and mild abnormal retinal blood vessel growth that converts to normal growth without treatment. Only approximately 1 out of 10 infants with early changes will progress to more severe retinal disease.

In the past, excess use of oxygen to treat premature babies stimulated abnormal vessel growth. Currently, oxygen can be easily and accurately monitored, and this is rare.

Today, the risk of developing ROP is proportional to the severity of prematurity. Typically all babies less than 32-34 weeks gestation are screened for the condition. However, only the smallest premature babies, no matter what their gestational age, have the highest risk.

Symptoms

Subtle retinal changes of ROP are visible only by ophthalmoscopic examination and cannot be seen by the parents. All premature infants are screened and followed routinely. Results of severe ROP may produce some of the following signs:

• white pupils (leukocoria)
  
• abnormal eye movements (nystagmus)
  
• crossed eyes (strabismus)
  
• severe nearsightedness (myopia)
  

Signs and tests

Retinopathy of prematurity can be diagnosed during examination by an ophthalmologist. Since there are few signs that ROP is developing, it is specially important to screen babies less than 32 weeks gestation.