Prevalence of Congenital Ocular Anomalies in 15 Countries of Europe: Results From the Medikeye Study

Background: Congenital ocular anomalies (COA) are among the most common causes of visual impairment in children in high-income countries. The aim of the study is to describe the prevalence of the various COA recorded in European population-based registries of CA (EUROCAT) participating in the EUROmediCAT consortium.
Methods: Data from 19 EUROmediCAT registries and one healthcare database (EFEMERIS) were included in this descriptive epidemiological study. Cases of COA included live births, FD from 20 weeks gestational age (GA), and termination of pregnancy for fetal anomaly.
Results: The prevalence of total COA was 3.47/10,000 births (95% CI [3.61-3.82]), ranging from 1.41 to 13.46/10,000 depending on the registry. Among COA cases, congenital lens anomalies were the most frequent anomalies (31%), of which over half were single ocular anomalies (presenting with only one ocular anomaly). An/microphthalmia was the second most frequent COA (24%) of which three-quarters were multiply malformed (associated to extraocular major anomalies). Among single COA cases, 58 were prenatally diagnosed (4%), of which, 58% were diagnosed in the second trimester. Known genetic causes of COA explained 2.5%-25% of COA depending on their class.
Conclusions: This is the first European study describing COA. The detailed prevalence data offered in this study could improve screening and early diagnosis of different classes of COA. As COA are rare, epidemiological surveillance of large populations and accurate clinical descriptions are essential.