Ocular component data in schoolchildren as a function of age and gender.
OBJECTIVE
To describe the refractive error and ocular components of a large group of school-aged children as a function of age and gender.


METHODS
In this report, we describe the refractive error and ocular components of 2583 school-aged children (49.3% girls, overall mean [+/-SD] age 10.0 +/- 2.3). Measurement methods included cycloplegic autorefraction, autokeratometry, videophakometry, and A-scan ultrasonography. For statistical comparisons across gender and age, a critical point of alpha = 0.005 was used to assess significance because of the large sample size and the large number of comparisons made.


RESULTS
Of these 2583 children, 10.1% were myopic (-0.75 D or more myopia in both meridians), and 8.6% were hyperopic (+1.25 D or more hyperopia in both meridians). As would be expected, there was a significant effect of age on refractive error (spherical equivalent, p < 0.0001), toward less hyperopia/more myopia. There was no significant difference in the average refractive error between girls and boys (p = 0.0192). Girls had steeper corneas than boys (0.74 D steeper in the vertical meridian and 0.63 D steeper in the horizontal meridian, p < 0.0001). There were no significant differences in corneal power with age (p = 0.16). Both older age and male gender were significantly associated with deeper anterior chambers (p < 0.0001 for both). The crystalline lens showed significant thinning with age (p < 0.0001), however, there was no significant difference in the lens thickness between girls and boys (p = 0.66). Both Gullstrand lens power and calculated lens power showed significant effects of age and gender (p < 0.0001 for both). Girls, on average, had Gullstrand lens powers that were 0.28 D steeper and calculated lens powers that were 0.80 D more powerful than boys. Axial length also showed significant effects of age and gender (p < 0.0001 for both). Girls' eyes were, on average, 0.32 mm shorter than those of boys.


CONCLUSIONS
These cross-sectional data show a general pattern of ocular growth, no change in corneal power, and crystalline lens thinning and flattening between the ages of 6 and 14 years. Girls tended to have steeper corneas, stronger crystalline lenses, and shorter eyes compared with boys.
Zadnik
Karla
K
The Ohio State University College of Optometry, Columbus, 43210-1240, USA. zadnik.4@osu.edu
Manny
Ruth E
RE
Yu
Julie A
JA
Mitchell
G Lynn
GL
Cotter
Susan A
SA
Quiralte
Julio C
JC
Shipp
Melvin
M
Friedman
Nina E
NE
Kleinstein
Robert  N
R
Walker
Terry W
TW
Jones
Lisa A
LA
Moeschberger
Melvin L
ML
Mutti
Donald O
DO
D000293:Adolescent; D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000886:Anthropometry / Q000379:methods; D002648:Child; D019781:Corneal Topography; D005123:Eye / Q000254:growth & development*; D005260:Female; D006801:Humans; D008297:Male; D012016:Reference Values; D012029:Refraction, Ocular / Q000502:physiology*; D012030:Refractive Errors / Q000175:diagnosis / Q000503:physiopathology; D012737:Sex Factors; D015351:Vision Screening / Q000379:methods; D014792:Visual Acuity / Q000502:physiology