Association of Smoking During Pregnancy and Birth Weight With RNFL Thickness in Preadolescence
JAMA Ophthalmology, April 2017
Smoking during pregnancy and low birth weight have been implicated in impaired development of the retina. Ashina et al. examined the specific relationship between these risk factors and the thickness of the retinal nerve fiber layer (RNFL) later in childhood. Both factors were found to be independently associated with a thinner RNFL in preadolescence.
At 11 or 12 years of age, participants of the Copenhagen Child Cohort 2000 Eye Study underwent examination of their right eye. RNFL thickness was measured using optical coherence tomography (OCT). Maternal smoking status was determined from interviews with the children’s parents. Birth weight and other relevant details were obtained from the Danish Medical Birth Registry. The main outcome was peripapillary RNFL thickness measured by OCT at the 11- or 12-year examination.
Among the 1,323 patients included in the analysis, mean RNFL thickness was 104 μm. The RNFL of children whose mothers had smoked while pregnant with them (n = 227) was 5.7 μm thinner than that of children whose mothers had not smoked, after adjustment of variables including age, gender, birth weight, current height/weight, axial length, and spherical equivalent refractive error, as well as self-reported Tanner stage. The RNFL in children with low birth weight (<2,500 g) was 3.5 μm thinner than that in children of normal birth weight, after adjustment of all variables. Other characteristics associated with a thinner RNFL were female sex, longer axial length, higher myopia, and shorter current stature.
These observations from a large cohort support others indicating that perinatal factors can have long-lasting effects on the retina and optic nerve. In conclusion, the authors’ findings augment the large body of evidence supporting the avoidance of smoking during pregnancy and the promotion of maternal and fetal health. (Also see related commentary by Christopher Kai-Shun Leung, MD, in the same issue.)
The original article can be found here.