Prevalence, pattern and associated factors of retinopathy of prematurity in the neonatal units at Kawempe National Referral Hospital and Mulago Specialised Women and Neonatal Hospital

Abstract

Introduction: Retinopathy of prematurity (ROP) is one of the leading causes of visual impairment and blindness among preterm babies. With approximately 226,000 preterm babies born annually and an increase in their survival rate due to advances in neonatal care in Uganda, there is a need to assess the burden, pattern and predictors of ROP to inform targeted screening for ROP hence the aim of this study. Methods: A cross-sectional study was conducted from August 2022 to October 2022 at the neonatal units of Kawempe National Referral Hospital (KNRH) and Mulago Specialised Women and Neonatal Hospital (MSWNH). Three hundred thirty one preterm infants (230 from KNRH and 101 from MSWNH) born before 37 weeks were consecutively enrolled into the study. The participants' relevant medical history and sociodemographic characteristics were captured from their parents and the medical records using a structured questionnaire. All participants underwent a fundus examination using an indirect ophthalmoscope with a +20D convex lens and Fundus imaging was done using a Volk iNview Fundus Camera. The collected data were entered into Epidata 4.2 and exported to STATA 14.0 for analysis. Study characteristics were summarized as mean, standard deviation, median and interquartile range for continuous variables, while categorical variables were presented as frequencies and proportions. Simultaneous association between the dependent and independent variables were assessed using logistic regression model and the level of significance considered was 5%. Results A total of 331 preterm babies with a mean gestational age was 30.4 weeks (SD = 2.7 weeks) were recruited in the study. The mean birth weight was 1597 grams (SD=509grams), while more than half (52.3%) of the preterm babies were female. Nineteen (5.7%) of the 331 had ROP, with almost all of them (18) recruited from MSWNH. Of the 19 participants, 8 (42.1%) had stage 2 ROP. Oxygen therapy was found to be the strongest risk factor in this study as all babies with ROP received oxygen (p-value < 0.0001). The odds of having ROP among neonates with a birth weight below 1500 grams were 10 times higher than those with birth weight of more than 1500 16 grams [AOR: 10.07 (2.71 – 37.44), p-value 0.001]. The neonates of chronological age earlier than five weeks were 3.7 times more likely to have ROP than those with chronological age of five or more weeks [AOR: 3.7 (1.26-10.93), p-value 0.018]. Besides, neonates who did not feed on breast milk exclusively had 7.8 times higher odds of having ROP than those given breast milk [AOR: 7.82(1.92-31.82), p-value 0.004]. Conclusion and recommendation We found that about every 6 in 100 preterms born in two tertiary hospitals in Uganda had ROP with 42% of them having stage 2 ROP. Long exposure to oxygen therapy, lack of exclusive feeding on breast milk, low birth weight of less than 1500 grams and chronological age of less than 5 weeks were strong predictors of ROP. We recommend that targeted ROP screening should be strengthened to identify those at risk/ cases and future research should focus on identifying the optimum duration of oxygen exposure in preterms.