Clinical features of comitant strabismus related to family history of strabismus or abnormalities in pregnancy and delivery.

PURPOSE To elucidate the genetic or environmental background for clinical features in the three major types of comitant strabismus. METHODS Interview based on a questionnaire asking background factors such as family history of strabismus and abnormalities in pregnancy and delivery was conducted with 101 consecutive patients with infantile esotropia (5-180 months of age), 83 with accommodative or partially accommodative esotropia (6-201 months of age), and 143 with intermittent exotropia (3-216 months of age) seen during 7 months from May to November 1998. The clinical features of strabismus obtained from medical records were analyzed statistically by logistic regression to determine their relation with these background factors. RESULTS In infantile esotropia, patients with family history of strabismus had a significantly higher chance of showing latent nystagmus (odds ratio, 3.553; 95% confidence interval [CI], 1.077-11.717; P =.0373, logistic regression analysis). In a subgroup of 40 patients with infantile esotropia whose birth followed no abnormalities in pregnancy or delivery, patients with family history of strabismus had a significantly higher chance of showing inferior oblique muscle overaction (odds ratio, 7.714; 95% CI, 1.246-47.761; P =.0280), dissociated vertical deviation (odds ratio, 6.667; 95% CI, 1.176-37.787; P =.0321), and latent nystagmus (odds ratio, 7.333; 95% CI, 1.168-46.060; P =.0336). In accommodative or partially accommodative esotropia and intermittent exotropia, no relation was found between the clinical features and the background factors. CONCLUSIONS Inferior oblique muscle overaction, dissociated vertical deviation, and latent nystagmus in infantile esotropia might have a genetic background.