Effect of body stature on refraction and ocular biometry in Chinese young adults: The Anyang University Students Eye Study.

CLINICAL RELEVANCE

Large-scale data on the association between body stature with biometry parameters and refraction in young adults facilitates an understanding of myopia development. Taller persons have eyes with more negative refractions, longer axial lengths, deeper anterior chambers, flatter corneas, and higher axial length-corneal radius ratio.

BACKGROUND

To determine the relationship between body stature with ocular biometry and refraction in young adults.

METHODS

This was a cross-sectional university-based study of 16- to 26-year-old students in China. Cycloplegic refraction and corneal curvature were measured using an autorefractor. Ocular parameters, including axial length, anterior chamber depth and lens thickness, were measured using a Lenstar LS900. Data on height and weight were acquired from an annual standardised physical examination and body mass index was calculated.

RESULTS

Of 7,971 participants examined in the school clinics, 5,657 (71.0 per cent) were available in the analysis. After adjusting for age, gender, parental myopia, time outdoors, near work and weight, each centimetre of height increase was associated with more negative refraction of -0.023-D, a 0.032-mm increase in axial length, a 0.003-mm increase in anterior chamber depth, a 0.008-mm increase in corneal curvature, and a 0.001 increase in axial length-corneal radius ratio. With regard to weight, a 1-kg heavier person was more likely to have less negative refraction of 0.011-D, a 0.001-mm increase in anterior chamber depth and a 0.002-mm increase in corneal curvature. A similar pattern of significant associations was also found in body mass index.

CONCLUSION

Taller, young adults tended to have longer eyes, deeper anterior chambers, flatter corneas, higher axial length-corneal radius ratio, and more negative refraction, adjusted for potential confounders. In contrast, heavier and higher body mass index persons are more hyperopic. The differences in stature may partially explain the variation in refraction and ocular biometric parameters.