Congenital esotropia in Olmsted County, Minnesota.

OBJECTIVE

To determine the birth prevalence of and risk factors associated with congenital esotropia.

DESIGN

Population-based prevalence study with nested case-control study.

PARTICIPANTS

All residents of Olmsted County, Minnesota who were diagnosed with congenital esotropia and born between January 1, 1980 and December 31, 1989 (n = 47). Control subjects were chosen by selecting the next two sequential births to parents residing in Olmsted County, Minnesota (n = 94).

METHODS

Cases were identified through the Medical Diagnostic Index of Mayo and the Rochester Epidemiology Project. The community medical records were reviewed to confirm case status and ascertain risk factor information.

MAIN OUTCOME MEASURE

Birth prevalence of congenital esotropia.

RESULTS

Forty-seven cases were identified from 17,536 live births, for a birth prevalence of 27 per 10,000 (95% confidence interval [CI], 20-35). Congenital esotropia was associated with prematurity (odds ratio [OR], 11.5; 95% CI, 3.4-39.2), a birth weight less than 2500 grams (OR, 4.6; 95% CI, 1.7-12.9), a low Apgar score at 1 minute (OR, 4.3; 95% CI, 1.7-11.2) and at 5 minutes (OR, 6.3; 95% CI, 1.3-30.7), and a family history of strabismus (OR, 3.5; 95% CI, 1.5-8.3).

CONCLUSIONS

The birth prevalence of congenital esotropia in Olmsted County, Minnesota is lower than previous estimates. Prematurity, low birth weight, low Apgar scores, and a family history of strabismus are significant risk factors for congenital esotropia.