Screening Criteria for Retinopathy of Prematurity in Ulaanbaatar, Mongolia

Abstract

Purpose : Blindness from retinopathy of prematurity (ROP) can be prevented with early identification and timely intervention. Low birthweight (BW) and early gestational age (GA) are the major risk factors for ROP. Neonatal mortality is decreasing in Mongolia, which will require evidence-based screening criteria for ROP. The purpose of this study is to describe BW and GA of children at risk for ROP in a cohort of patients in Mongolia and identify potential evidence-based ROP screening criteria.

Methods : 193 neonates, ≤36 weeks and/or ≤2000g at the National Center for Maternal and Child Health in Ulaanbaatar, Mongolia, were included in this prospective study. ROP screening exams to determine ROP status and severity were performed. Data was collected using a secure web-based system between December 1, 2015 and January 31, 2017. BW and GA were categorized based on their quantile distribution, BW (≤1200g, between 1201 and 1699, and ≥1700) and GA (≤29 weeks, between 30 and 31, and ≥32). Log-binomial regression analysis was performed to determine the relative risk and confidence intervals between BW and ROP status and GA and ROP status.

Results : Seventy-five infants (39%) developed ROP and 44 infants developed Type 2 or worse ROP. Four infants progressed to stage 4 and no children progressed to stage 5. Of those with ROP, the highest severity reached was mild in 31 infants, Type 2 in 14 infants, and Type 1 in 30 infants. The distribution of BW and GA of infants with ROP is shown in Table 1. The relative risk of developing any stage ROP and Type 2 or worse ROP increased as BW and GA decreased (Table 2). The heaviest infant treated had a BW of 2000g and the oldest infant treated had a GA 34 weeks.

Conclusions : The incidence of ROP in Mongolia is similar to other low to middle income countries. ROP was seen in infants with larger BW and older GA relative to high income nations. The distribution of BW and GA in this cohort did not match existing screening criteria in higher income countries, indicating that screening criteria should be based on the population in which it will be implemented. Screening infants ≤34 weeks and/or ≤2000g would capture the cases of treatment-requiring ROP in the group of patients that were analyzed in this study. This recommendation is limited by the assumption that all clinical data was captured accurately and that GA was measured accurately.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.