Retinopathy of Prematurity (ROP) is a retinal disorder seen in prematurely born babies which if left untreated can lead to a lifetime of total blindness.

Retina is the part of the eye on which the image forms before it is sent to the brain to interpret. So it is like the film of a camera. This film, i.e. retina is a living film and has a blood supply. ROP is a disorder of abnormal development of this blood supply of the retina. The blood supply of the retina starts developing while the baby is in the mother's womb. Blood vessels start forming near the nerve of the eye which is close to the center of the retina. The blood vessels then proceed towards the circumference of the retina, which they almost reach by the time the baby is full term. In pre-mature babies the blood vessels have not reached very far towards the circumference. In case the growth of these vessels gets arrested, ROP is said to occur. Subsequently in children with ROP, abnormal blood vessels start developing in the retina. These abnormal vessels can cause bleeding in the eye or even pull the retina and detach it from its place. Imagine how severe the vision loss would be if the film (retina) is not in place or has blood in front of it.

What causes it and who is at risk?

The exact cause of this maldevelopment of blood vessels in pre-mature infants is not known. But infants who are at risk are -

• Infants with a birth weight of less than or equal to 1500 gm

• Gestational age of 34 weeks or less (i.e., premature birth before completion of 34 weeks of pregnancy)

• Infants more than 1500 gm with an unstable clinical course felt to be at high risk by their attending pediatrician or neonatologist.

• Babies at higher risk for ROP apart from the above include –
   

  • Exposure to oxygen for more than 30 days

  • Respiratory distress syndrome

  • Sepsis

  • Multiple blood transfusions

  • Multiple births

  • Apnoeic episodes

How is it diagnosed?

As the disease is of pre-mature infants, it is mandatory that all newborn nurseries should have a protocol to have the eyes of babies at risk examined by a retina specialist.

A retina specialist or a pediatric ophthalmologist can detect ROP by examining the retina after dilation of the child's pupil.

This examination can be carried out in the nursery itself. The examination is not very uncomfortable for the child as anaesthesia drops are put in the eyes before examining to prevent pain. The first eye examination should generally be done within 4 weeks of the birth of the child. Subsequent follow up examinations till the retina of the baby is fully mature are done as desired by the eye specialist.

What is the treatment of Retinopathy of Prematurity?

Fortunately early stages of ROP are reversible on their own in many babies. But if the disease reaches a particular threshold then it is better to treat with LASER to prevent vision threatening / blinding complications. LASER can be done in the nursery itself in a few sessions. The response to LASER in most cases is very good. In case LASER fails, there are a few surgical options available. However, the results of these surgeries are not very encouraging.

What are the outcomes?

The outcome of timely Retinal Laser Photocoagulation is generally very good with few side-effects.

What are the complications?

In case no treatment is done and the ROP keeps progressing, it will ultimately pull the retina leading to retinal detachment. There can also be bleeding within the eye or vitreous hemorrhage. This finally leads to near total blindness.

Author: Dr. Rohan Chawla
Date: 27 November 2008