Introduction

Retinopathy of prematurity (ROP) is a disease due to abnormal development of blood vessels in the eyes of premature babies. Blood vessels in the eyes start to grow on the retina (nerve layer of the eye) at 4 months of pregnancy. It’s completed when pregnancy reaches its term. When a child is born prematurely, the normal development gets disrupted. Abnormal blood vessels cause bleeding and leakage onto the retina. Retina is important for normal vision. Disruption of the retina layer may cause scarring and detachment which may lead to blindness.

Risk factors:

• Degree of prematurity
  The smaller the baby at birth, the higher the risk. This is the most important risk factor for development of ROP.
• Oxygen use
  The relationship between oxygen exposure and ROP is complex. With modern neonatal care and better monitoring of oxygen level, this risk factor has diminished in importance.
• Baby’s general condition
  A sick premature baby has a higher risk to develop ROP.

Symptoms & Signs

ROP has 5 stages. Stage 1 is mild disease, whereas Stage 5 is severe and causes blindness. Most babies only get a mild form of ROP which will resolve completely by itself. Some babies may progress and require treatment to prevent vision loss or blindness.

Treatment is needed when there is Stage 3 or above. There are various methods of treatment available which are effective and successful.

There is no outward signs or symptoms for early ROP. It can only be detected by eye examination through dilated pupils. Babies who are born earlier than 8 months (32 weeks) of pregnancy and weigh less than 1.5kg should routinely have their eyes examined.

Screening

The first eye examination is usually done 4-6 weeks after birth. The screening is usually done before the baby is discharged from hospital or soon after discharge. Subsequent follow-up will depend on the findings of the first examination. Some babies need to come to the eye clinic on an outpatient basis for further examination. Parents should know what follow-up eye exams are needed before the baby leaves the hospital.

Screening for ROP is important. It helps in early detection and prompt treatment of ROP for optimum visual outcome.

Treatment

• Laser treatment
  Laser treatment uses heat energy to ‘burn away’ the peripheral area of the retina to stop the growth of the abnormal blood vessels.
• Cryotherapy
  This form of treatment uses an instrument that produces ice-balls to freeze the surface of the eye overlying the peripheral retina.
  Both laser and cryotherapy scarred the peripheral retina to save the central retina which is important to preserve vision.
• Surgery
  In severe (Stage 4 and 5) ROP surgery may be needed to flatten back a detached retina. Surgery may preserve some vision but may not result in good vision.
  The baby will be given sedation or be under general anaesthesia to ensure that the baby will not feel any pain during the procedure.

Outcomes

The most important factor in the outcome is early detection and treatment. Early treatment can improve a baby’s chance for normal vision. However, not all babies respond to treatment. Up to 25% of babies who had ROP treatment may still lose some or all vision.

Babies with ROP are at a higher risk to have certain eye problems in life. These include near-sightedness, squint or crossed eyes, lazy eye, glaucoma (high eye pressure) or retinal detachment. All babies with ROP should have regular yearly eye examination until discharged from follow-up.

Prevention

The most effective way to avoid development of ROP is prevention of premature birth especially below 28 weeks of gestational age. Mild ROP is therefore not always preventable.

Rehabilitation

Babies with severe visual impairment related to ROP may have other complications of prematurity. They may require multi-disciplinary approach to rehabilitation.

Parents of children with visual disability can seek assistance from;

1. Department of Social Welfare – http://www.jkm.gov.my
2. Malaysian Association for the Blind (MAB) – http://www.mab.org.my

References:

1. Ministry of Health Malaysia and Academy of Medicine Malaysia. (2005) Clinical Practice Guidelines: Retinopathy of Prematurity. MOH/P/PAK/103.05(GU) Available on http://www.moh.gov.my.
2. Section on Ophthalmology American Academy of Pediatrics, American academy of Ophthalmology and Strabismus. Screening examination of premature infants for retinopathy of prematurity. Pediatrics. 2006 Feb; 117(2):572-6.

Other Resources

1. http://www.nei.nih.gov/health/rop
2. http://wwwnlm.nih.gov/medlineplus/ency/article/001618.htm
3. http://kidshealth.org/parent/system/surgery/rop.html