Eye anomalies: seasonal variation and maternal viral infections.

INTRODUCTION: Eye anomalies, including anophthalmos and microphthalmos (absent eye and small eye), are common features in congenital infection syndromes such as rubella. Influenza, Coxsackie virus, and Parvovirus are less well-established teratogens. We report an ecologic analysis of anophthalmia/microphthalmia prevalence in England in relation to temporal variation in these infections using routine infection data.
METHODS: The national (England) anophthalmos/microphthalmos register holds details of 406 babies (excluding chromosomal anomalies) born 1988-1994. Weekly infection data were obtained from the U.K. Public Health Laboratory Service and Royal College of General Practitioners Weekly Returns Service. We assigned cases and births an estimated exposure based on the population infection counts in the gestational weeks known to be critical for ocular development. We calculated the rate ratio of anophthalmos/microphthalmos prevalence for infection in the 90th percentile compared with the 10th percentile by Poisson regression.
RESULTS: There was a positive association between severe anophthalmos/microphthalmos prevalence and Parvovirus B19 (rate ratio = 1.26; 95% confidence interval = 1.00-1.58) and for influenza (1.41; 1.08-1.84). Coxsackie virus showed a negative association with any anophthalmos/microphthalmos (0.75; 0.58-0.98) and with severe cases (0.66; 0.46-0.95).
CONCLUSIONS: This analysis provides suggestive evidence for a teratogenic role of influenza and Parvovirus in anophthalmos/microphthalmos. The role of maternal infections in congenital anomaly etiology is worthy of further investigation.