European Academy of Optometry and Optics

Academy 2023, Poznan

Authors: Síofra Harrington, Veronica O’Dwyer

Abstract
Purpose: Myopia and childhood obesity are growing health problems, and the adverse effects of obesity on visual function and refractive status in children in Ireland are unknown. This study explored the relationship between body mass index (BMI), refractive error, ocular biometrics and visual function in Irish 6-7-year-olds.
Methods
Participants were 728 6-7-year-olds (377 boys (51.8%)) in Irish schools. The examination included logMAR visual acuity (VA) (presenting and pinhole), stereoacuity (TNO stereo-test), cycloplegic autorefraction (1% cyclopentolate HCL), and ocular biometry (Zeiss IOLMaster), height (cm) and weight (kg). Power vector analyses of Cartesian (J0) and oblique (J45) astigmatism components of refractive, corneal astigmatism.
Results
BMI (weight/height’) was positively correlated with stereoacuity (arc-secs) (r = 0.212, p <0.001), logMAR VA at 3m (r = 0.102, p=0.006), at 40cm (r = 0.110, p = 0.005), pinhole VA (r = 0.109, p= 0.003), corneal (r = 0.113, p=0.002) and refractive (r = 0.118, p = 0.001) JO astigmatism, and negatively correlated with anterior chamber depth (r = -0.266, p = 0.01). Nineteen per cent (139 participants) were overweight/obese. Socioeconomic disadvantage (Odds Ratio (OR) = 2.18, 95% confidence intervals (CI):1.50 to 3.18, p <0.001), and non-White ethnicity (OR=2.09, CI: 1.25 to 3.49, p<0.001), were associated with overweight/obesity. Controlling for confounders, overweight/obesity was associated with myopia (≤-0.50D) (OR=2.90, Cl:1.13 to 8.77, p=0.026), premyopia (>-0.50D ≤0.75D) (OR= 1.68, Cl:1.03 to 2.73, p=0.037), astigmatism (≥ 1D) (OR=2.06, Cl:1.14 to 3.71, p=0.016), visual impairment (VI) (VA>0.3LogMAR) (OR=3.19, Cl:1.49 to 6.82, p=0.003), abnormal stereoacuity (≥240 arcsecs) (OR=2.96, Cl:1.49 to 5.14, p<0.001). Healthy weight was associated (OR=2.84, Cl:1.13 to 7.14, p=0.027) with clinical emmetropia (>0.75,≤2.00D).
Conclusions
Higher BMI was associated with poorer visual and stereoacuity. Overweight/obese children were three times more likely to be visually impaired or myopic and twice as likely to be premyopic or astigmatic. Emmetropia was associated with a healthy weight. Addressing children’s visual issues is essential to preventing obesity. Socioeconomically disadvantaged and ethnic minority children will benefit most from interventions.