Introduction
Retinopathy of prematurity (ROP) is a vasoproliferative disorder that affects the developing retinal vessels of premature newborns.1 ROP is a leading preventable cause of blindness in children, particularly in middle-income countries. In 2010, the annual incidence of blindness and vision impairment due to ROP was estimated to be 32 300 infants.2
In sub-Saharan Africa, ROP is beginning to emerge as a cause of blindness in children as neonatal intensive care services expand.3
The risk of ROP is inversely related to gestational age (GA) and birth weight (BW) and the risk is higher in those with neonatal comorbidities.4 Poorly monitored supplemental oxygen leading to hyperoxia is a recognised risk factor for treatment-requiring ROP,5 as are low serum IGF-1, poor postnatal weight gain, sepsis, blood transfusion4 and thrombocytopenia.6
In high-income countries, treatment-requiring Type 1 ROP usually only affects extremely preterm (<30 weeks), low BW (<1000 g) infants, with the risk being much lower in more mature preterm infants.5 These findings reflect the high quality of perinatal and neonatal care these infants receive. In low-income countries, rates of Type 1 ROP can also be low, as most infants at risk do not survive. A different picture is seen in middle-income countries, where neonatal care can be suboptimal, and infants are exposed to risk factors, such as poorly regulated supplemental oxygen and sepsis, which are largely controlled in high-income settings. In middle-income countries, rates of Type 1 can be high, and can affect infants with a GA of >34 weeks or BW of >1500 g.3 7 8 The same picture is beginning to emerge in sub-Saharan African countries,9 where neonatal care is developing and expanding, but where infants can be exposed to poorly regulated oxygen and other risk factors.
In 2014, the global preterm birth rate was estimated to be 10.6%, with 14.84 million live preterm births; Asia and Sub-Saharan Africa accounted for 12 million preterm births (81.1%).10 Survival rates for preterm infants have improved in many low-income and middle-income countries as neonatal systems have improved. ROP has not been documented as a significant cause of blindness in low-income countries, but the expansion of neonatal care11 12 has increased survival and hence the risk of developing ROP. In Africa, South Africa, Nigeria and Kenya have ROP screening guidelines.9 13 14
Ethiopia planned to reduce neonatal mortality from 28/1000 in 2015/2016 to 10/1000 in 2019/2020, and to end preventable deaths among newborns and children under 5 years by 2030.15 Ethiopia is the second most populous country in Africa, and 11.4% of births are preterm (<37 weeks of gestation), that is, approximately 320 000 babies each year.16 Before 2020, blindness from ROP was not reported in Ethiopia, including from studies in school for the blind.17 18 However, in 2020, a retrospective study by a paediatric ophthalmologist in a private eye centre showed that 12.9% of the infants born preterm who presented were blind from advanced ROP.19 The study was undertaken in two neonatal intensive care units (NICUs) in the capital city, Addis Ababa: Tikur Anbessa Specialized Hospital (TASH), which is a leading government owned university teaching hospital, and Menelik II, a government referral hospital. The purpose of this prospective study was to determine the proportion of preterm newborns who develop ROP, to identify risk factors for ROP and to describe the outcomes of ROP management.