Perinatal Risk Factors for Strabismus

Tobias Emil Torp-Pedersen (1) , Heather Allison Boyd (2) , Gry Poulsen (2) , Birgitte Haargaard (3) , J Wohlfahrt (2) , M Melbye (2) , Jonathan M Holmes (4)

1 Dept. of Epidemiology Research
2 Dept. of Epidemiology Research
3 Dept. of Ophthalmology
4 Dept. of Ophthalmology

Background: Little is known about the etiologic factors underlying strabismus. We undertook a large cohort study to investigate perinatal risk factors for strabismus, overall and by subtype. Methods: Orthoptists reviewed ophthalmologic records for Danish National Birth Cohort children examined for strabismus in hospital ophthalmology departments or by ophthalmologists in private practice. Information on perinatal characteristics was obtained from national registers. We used log-linear binomial regression and polytomous logistic regression to estimate risk ratios for strabismus overall and by strabismus subtype, respectively. Results: Among 96 842 DNBC children born in Denmark between 1996 and 2003, we identified 8783 children who had been evaluated for strabismus. Ophthalmologic records were available for 5655 of these children, of whom 1321 were diagnosed with strabismus. In multivariable analysis, low birth weight, prematurity, large head circumference and presence of congenital abnormalities were all associated with increased risk of strabismus. Presence of congenital abnormalities was more strongly associated with exotropia than with esotropia. Of 183 exotropia cases, 40 (22%) had a congenital abnormality. While not associated with esotropia, delivery by Cesarean section was associated with exotropia (RR=1.65; 95% CI 1.16-2.34). After adjustment for birth weight, Apgar score at five minutes, multiple gestation and parental ages were not associated with strabismus overall. Conclusions: Congenital abnormalities, low birth weight, prematurity, and large head circumference were independent risk factors for strabismus. Differences in risk factors for esotropia and exotropia suggest that strabismus subtypes may have different underlying etiologies. The proportion of exotropic children with congenital abnormalities suggests that a large angle constant exotropia in an infant should alert physicians to the possibility of a congenital malformation.

Mots clés: Medicine

Tobias Emil Torp-Pedersen, Heather Allison Boyd, Gry Poulsen, Birgitte Haargaard, J Wohlfahrt, et al.. Perinatal Risk Factors for Strabismus. International Journal of Epidemiology, 2010, ⟨10.1093/ije/DYQ092⟩. ⟨hal-00598088⟩