Contribution by Dr Mary Ugalahi – a consultant Paediatric Ophthalmologist
Last week, we read about the heart rendering story of how Iveren, after a very long wait to conceive, gave birth prematurely to baby Precious. Unfortunately, because she refused to have Precious examined soon during the critical four weeks after birth, owing to ignorance, Precious subsequently became blind from Retinopathy of Prematurity (ROP).
What is Retinopathy of Prematurity (IOP)? How does it develop? How can it be prevented? Dr. Ugalahi will answer these questions and more in this article.
Retinopathy of prematurity (ROP) is an abnormal proliferation of vessels in the retina (inner coat of the eye) affecting mostly preterm babies (babies born too soon). Without early recognition and treatment, it is a potentially blinding disease and the leading cause of preventable childhood blindness worldwide.
The World Health Organisation (WHO) estimates that about 15million babies are born preterm (gestational age less than 37weeks) annually. Nigeria places third in the number of preterm births, with about 773,600 preterm births according to latest figures by WHO (2018).
About 10 to 15 per cent of babies born in Nigeria annually are born preterm. With improved effort in neonatal intensive care units in low and middle income countries of which Nigeria is one, more preterm babies are surviving and expectedly the incidence of ROP is rising.
The first epidemic of retinopathy of prematurity occurred in the 60s and 70s in high income countries. This led to the establishment of National guidelines for screening of babies born preterm with effective treatment of identified babies. This was followed by a second wave of ROP epidemic also noticed in high income countries as neonatal services improved and extreme low birth weight babies survived.
The third wave of ROP epidemic is being seen in developing countries. This is especially important as UNICEF increases its activity of improving neonatal services in these countries. Nigeria currently does not have a national policy on ROP screening and treatment.
Efforts are underway by the Nigerian Paediatric Ophthalmology and Strabismus Society (NIPPOSS), a body saddled with the care of eye diseases in children to develop a screening guideline appropriate for our environment.
The absence of a National Programme for screening of preterm babies for ROP is worrisome as it implies a lifetime of blindness for such children if not treated with associated lack of economic productivity for the family and the country as a whole.
Who gets ROP? Preterm babies are at risk of retinopathy of prematurity. However a lot of studies have shown that certain preterms are more at risk and as such should be screened.
These include, babies born at gestational age 32 weeks and below or weighing 1500g or less and babies born less than 37 weeks or weighing 2000g with associated risk factors in the perinatal period which may predispose them to ROP.
Why do preterm babies develop ROP? The blood vessels on the retina starts developing on the 16th week of gestation (pregnancy). This continues until term. If a baby is born before term (37 to 40 weeks) the retinal vessels are very immature and in the presence of any of the factors above there is stimulation of the growth factor responsible for normal vascular development. So, abnormal vessels develop.
These abnormal vessels leak their content (blood) easily, leading to inflammation, fibrosis, traction and detachment of the retina, hence resulting in total visual loss in the baby. Screening and early treatment ensures the disease does not run its course and lead to blindness.
How is screening done? ROP screening is a team effort. The team comprises of the parents of the preterm, the preterm baby, a neonatologist, neonatal nurses, an ROP coordinator and an ophthalmologist.
The neonatal nurse and neonatologist are responsible for identifying children who need screening and contacting the ophthalmologist.
The ROP co-ordinator, who may be a neonatal nurse, counsels the parents of the preterm and prepare them for the screening process. The ophthalmologist, preferably is a paediatric ophthalmologist or a vitreoretinal specialist does the screening weekly as scheduled in each facility. This ensures babies are not missed.
The first screening should be within four weeks after birth and subsequently as required. The main tool for screening is the ophthalmoscope, which is usually mounted on a head band. It incorporates the use of a strong light which does not hurt babies’ eyes.
This was the erroneous impression that caused Iveren disallowing her baby from being screened. Babies identified with ROP that meets treatment criteria should be treated after counselling.
Apart from ROP, preterm babies are also at risk of high refractive errors, strabismus and amblyopia. These should also be screened for and treated appropriately.
How can blindness from ROP be prevented? Prevention of ROP is a collaborative effort involving all who care for preterm babies; the gynaecologist, midwives, neonatologist, neonatal nurses, ophthalmologists and the parents. Reducing preterm deliveries reduces the number of babies at risk.
This is very pertinent now as fertility treatment centres become more abundant in the country. Other measures include provision of standard perinatal and neonatal care with modern infrastructures and equipment country-wide, the use of telemedicine to screen the not easily reached areas.
The training of the relevant personnel for screening and provision of equipment for screening and treatment should be a priority for government.
The importance of parental education, awareness and motivation to ensure that at risk babies are screened and followed up properly cannot be over-stressed.
Finally, a national screening and treatment guideline for Nigeria should, as a matter of urgency, be developed. Prevention of ROP is everyone’s business.