# Optic disc parameters and associations with early life exposures in over 3000 12-year-old children: findings from the ALSPAC cohort

## TL;DR

This study found that optic disc size and shape in children are linked to early-life factors like prematurity, low BMI, maternal smoking, and small head circumference, suggesting these factors may affect long-term eye health.

## Contribution

The study is the first to report the frequency and risk factors for small optic discs and high cup-to-disc ratios in children using a large cohort.

## Key findings

- Severely premature children and underweight children have a significantly higher odds of having a high cup-to-disc ratio.
- Maternal smoking during pregnancy and small head circumference at birth are associated with increased odds of small optic discs.
- Optimization of prenatal and early childhood factors may influence ocular neurodevelopment and lifelong eye health.

## Abstract

We aimed to investigate the distribution of small optic discs and large cup-to-disc ratio in children and to examine associations with maternal and environmental factors.

Retinal photographs were graded from over 3000 12-year-olds in the Avon Longitudinal Study of Parents and Children. Regression models examined associations between disc parameters and maternal and early-life exposures.

Mean cup-to-disc area ratio (CDAR) for 3288 children was 0.21 (95%CI 0.20,0.21). Discs with CDAR > 0.3 were present in 11%. The odds of CDAR > 0.3 were increased nearly three-fold in underweight children (adjusted odds ratio (aOR) 2.9 (1.1, 7.3) p = 0.03) and 28-fold in severely premature ( < 28 weeks) children (paOR 28 95%CI 4.6,172, p < 0.001) with nearly one in four children affected. Mean cup-to-fovea/disc diameter (CF/DD) for 3327 children was 2.48 (95%CI 2.47,2.50). Small discs (CF/DD > 3) were present in 6% of which a third were bilateral. The odds of a small disc were increased in the offspring of mothers who smoked in pregnancy (aOR 1.7 (1.0,2.8) p = 0.04) and more than doubled in children born with a small head circumference (aOR 2.5 (1.4,4.5) p < 0.001).

Small optic discs and high cup-to-disc ratio are more frequent than usually supposed at age 12. The odds of CDAR > 0.3 are increased by severe prematurity and pathologically low child BMI. The odds of a small disc are increased by maternal smoking and small head circumference. Optimisation of risk factors in pregnancy and delivery and early childhood nutrition may play an important role in ophthalmic neurodevelopment and thus have a lifelong impact on ocular health.