Validation of the existing modified screening criteria for detection of all cases of Retinopathy of Prematurity in preterm babies – 11 year study from a governorate referral hospital in Oman

PURPOSE: To study appropriateness of our modified screening criteria for detection of all cases of Retinopathy of Prematurity (ROP) among preterm babies. METHOD: Retrospective observational cohort study among preterm neonates who underwent ROP screening as per set protocol for 11 years at Nizwa Hospital, Al Dhakilya Governorate, Oman. We screened all babies with gestational age ⩽32 weeks or BW ⩽ 1500 g. Preterm babies >32 weeks of GA or BW > 1500 g with unstable clinical course believed to be at high risk by the attending neonatologist also were screened. RESULTS: During the study period 528 babies were screened for ROP of which 76 babies were excluded due to death, associated congenital ocular malformation and loss for follow-up either due to transfer to other institution or defaulting. Thus 452 babies were included in the final analysis. Incidence of ROP was 46.4% of which 27.9% had mild ROP, 11.3% had severe ROP which regressed and 7.3% had severe ROP who were treated. The incidence of ROP among infants with GA < 26 wks, 26–28 wks, 29–30 wks, 31–32 wks and above 32 weeks was 100.0%, 80.0%, 59.3%, 34.4% and 19.4% respectively. 56 babies of this cohort belonged to Extended (modified) criteria group. Among these 12 babies had ROP out of which 9 had mild ROP and 3 had severe ROP. Among cases with severe ROP, two cases regressed spontaneously and one case needed treatment. Multivariate analysis using stepwise regression model showed statistically significant association of GA and BW to development of ROP. We would have missed few babies with ROP if we had followed other criteria. CONCLUSION: Our modified screening criteria seem to be appropriate as no infant with severe ROP was missed during the study period. Incidence of severe ROP among babies in the extended criteria group (5.4%) is low but significant compared to lower gestational age. We plan to formulate a scoring system following all risk factor analysis to enable us to optimize the number of infants screened. Detection of all babies with ROP is important as they need long-term follow-up for the timely detection and management of associated ocular comorbidities.