Ocular Associations of Low Birth Weight and Prematurity in 12-year-old Children

1. Yasser M. Tariq
2. Amy Pai
3. Erdahl Teber
4. Paul Mitchell

Centre for Vision Research, Westmead Millennium Institute, University of Sydney, Sydney, Australia.

Purpose: To determine the associations of low birth weight and prematurity with ocular biometry and ocular morbidity in 12-year-old Sydney school children, and to compare with previously reported findings in 6-year-old children.

Methods: Random-cluster sampling was used to recruit 2367 year 7 students from 21 secondary schools in Sydney, Australia. Eye examinations included assessment of visual acuity (using LogMAR charts), cover tests, keratometry, biometry (IOLMaster) and cycloplegic autorefraction (Canon RK-F1). Parental questionnaires on socio-demographic information and birth history were collected. Logistic regression and mixed models were utilized in data analyses with adjustments for age, sex, height, ethnicity and cluster sampling.

Results: At 12 years of age, the odds for myopia, hyperopia, amblyopia, astigmatism, strabismus and anisometropia, did not significantly differ by birth weight category or prematurity (all p>0.05). By comparison, 6-year-old children with low birth weight or prematurity had increased odds of strabismus and amblyopia. In continuous models for 12-year-old children, increased birth weight was associated with increased axial length, anterior chamber depth and corneal radius (mixed model coefficient 0.15mm/kg, p<0.0001; 0.03mm/kg, P=0.006 and 0.06mm/kg, p<0.0001, respectively). There was a borderline association with increased cylindrical power (p=0.05), but no association with spherical equivalent refraction (p=0.33). Similarly, birth weight was positively correlated with axial length and corneal radius in 6-year-old children.

Conclusions: The increased ocular morbidity associated with prematurity and low birth weight reported in 6-year-old children were not apparent in the 12-year-old sample, although the associations of birth weight with ocular biometry were consistent in both age groups.