Incidence of Strabismus in a Danish Pediatric Population
JAMA Ophthalmology, October 2017
Population-based research on the incidence of strabismus is limited. Torp-Pedersen et al. examined data for young Danish children (≤ 7 years of age) and attained results comparable to those of smaller European and U.S. studies, but the ratio of esotropia to exotropia was higher in their study.
The authors reviewed records for 96,842 children enrolled in the Danish National Birth Cohort. Primary outcomes were age-specific incidence of strabismus, cumulative incidence of strabismus, and median age at detection (overall and by subtype).
All told, the researchers identified 1,309 cases of strabismus. The overall cumulative incidence of strabismus was 2.56% at age 7, and it was similar for boys and girls. The most common subtypes identified were congenital esotropia (16.5%, n = 216), fully accommodative esotropia (13.5%, n = 177), partially accommodative esotropia (19.3%, n = 252), and exotropia (13.8%, n = 181). The ratio of esotropia to exotropia was 5.4:1, which is higher than that observed in smaller studies. Other differences from previous findings were a lower incidence of central nerve system–associated strabismus and a greater incidence of congenital esotropia.
Age-specific incidence curves for congenital esotropia, fully accommodative esotropia, partially accommodative esotropia, and all exotropia suggested that the various subtypes have different age-specific incidence patterns (p < .001 for all pairwise comparisons of curves). The median age at detection of these 4 common subtypes was 0, 32.0, 26.1, and 16.6 months, respectively. Gender differences, which were nominal, were observed for only 3 subtypes (accommodative esotro pia; microesotropia; and intermittent esotropia). (Also see related commentary by Scott R. Lambert, MD, in the same issue.)
The original article can be found here.