Children’s Ocular Components and Age, Gender, and Ethnicity

Abstract

Purpose This cross-sectional report includes ocular component data as a function of age, gender, and ethnicity from the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study. Methods The ocular components of 4881 school-aged children were examined using cycloplegic autorefraction (refractive error), keratometry (corneal curvature), ultrasonography (axial dimensions), and videophakometry (lens curvature). Results The average age (± SD) was 8.8 ± 2.3 years, and 2458 were girls (50.4%). Sixteen percent were African American, 14.8% were Asian, 22.9% were Hispanic, 11.6% were Native American, and 34.9% were White. More myopic/less hyperopic refractive error was associated with greater age, especially in Asians, less in Whites and African Americans. Corneal power varied slightly with age, with girls showing a greater mean corneal power. Native-American children had greater corneal toricity with a markedly flatter horizontal corneal power. Anterior chambers were deeper with age, and boys had deeper anterior chambers. Native-American children had the shallowest anterior chambers and Whites the deepest. Girls had higher Gullstrand and calculated lens powers than boys. Boys had longer vitreous chambers and axial lengths, and both were deeper with age. Native Americans had the longest vitreous chambers and Whites the shortest. Conclusions Most ocular components showed little clinically meaningful variation by ethnicity. The shallower anterior chambers and deeper vitreous chambers of Native-American children appeared to be offset by flatter corneas. The relatively deeper anterior chamber and shallower vitreous chambers of White children appeared to be offset by steeper corneas. Asian children had more myopic spherical equivalent refractive errors, but for a given refractive error the ocular parameters of Asian children were moderate in value compared to those of other ethnic groups. Asian children may develop longer, myopic eyes more often than other ethnic groups, but the eyes of Asian emmetropes do not appear to be innately longer.

Body Stature Growth Trajectories during Childhood and the Development of Myopia

“…For instance, an above-average rate of increase in height up until the age of 10 was associated with a longer AXL at age 15, whereas only growth velocities during the first few years of life were predictive of RCC at age 15. This suggests that early growth is more important in determining RCC in young adulthood than is the case for AXL, which is consistent with the virtual cessation in RCC growth seen in both cross-sectional and longitudinal studies after the first few years of life, compared to the continued elongation of the globe 10,14,55,56 . The association between stature and eye size has led to the suggestion that genetic variants known to influence height might also influence axial length 25,56,57 .…”

“…This suggests that early growth is more important in determining RCC in young adulthood than is the case for AXL, which is consistent with the virtual cessation in RCC growth seen in both cross-sectional and longitudinal studies after the first few years of life, compared to the continued elongation of the globe 10,14,55,56 . The association between stature and eye size has led to the suggestion that genetic variants known to influence height might also influence axial length 25,56,57 . However, we found no evidence that a group of common SNPs that explain ~10% of the variation in adult height 27 and 5-6% of the variation in height by age 10 years 41 was predictive of AXL.…”

Axial Length and Associated Factors in Children: The Shandong Children Eye Study

“…Associations of longer AL with older age and with male gender were also found in previous studies [3,12,13]. To cite an example, in the Collaborative Longitudinal Evaluation of Ethnicity and Refractive Error (CLEERE) Study and in the Sydney Myopia Study, longer AL was associated with older age of the children [3,13,14]. In the Asian subpopulation of the CLEERE Study, mean AL was 22.82 mm for boys and 22.33 mm for girls at an age of 6 years.…”

“…In the Asian subpopulation of the CLEERE Study, mean AL was 22.82 mm for boys and 22.33 mm for girls at an age of 6 years. These values were slightly higher than the AL measurements obtained in our study on children of the same age (boys: 22.65 ± 0.76 mm; girls: 22.25 ± 0.66 mm) [14]. In the Sydney Myopia Study as compared to our study, mean AL as measured by ocular biometry (IOLMaster, Carl Zeiss Meditec AG) was slightly longer for the 6-year-old children (22.58 vs. 22.49 ± 0.75 mm) and shorter for the 7-year-old children (22.67 vs. 22.76 ± 0.79 mm) [3].…”

Ocular biometry and central corneal thickness in children: a hospital-based study

“…This finding is consistent with Zadnik et al, who reported that AL was longer in boys (10) . Twelker et al and Ojaimi et al studied AL in school-age children and reported the same findings (11,12) . In our study, lens thickness was 3.67 mm in the first 2 years of life and 3.51 mm in 11-12 years (Graphic 2).…”