Anisometropia prevalence in a highly astigmatic school-aged population.
OBJECTIVE
To describe prevalence of anisometropia, defined in terms of both sphere and cylinder, examined cross-sectionally, in school-aged members of a Native American tribe with a high prevalence of astigmatism.


METHODS
Cycloplegic autorefraction measurements, confirmed by retinoscopy and, when possible, by subjective refraction were obtained from 1041 Tohono O'odham children, 4 to 13 years of age.


RESULTS
Astigmatism > or =1.00 diopter (D) was present in one or both eyes of 462 children (44.4%). Anisometropia > or =1.00 D spherical equivalent (SE) was found in 70 children (6.7%), and anisometropia > or =1.00 D cylinder was found in 156 children (15.0%). Prevalence of anisometropia did not vary significantly with age or gender. Overall prevalence of significant anisometropia was 18.1% for a difference between eyes > or =1.00 D SE or cylinder. Vector analysis of between-eye differences showed a prevalence of significant anisometropia of 25.3% for one type of vector notation (difference between eyes > or =1.00 D for M and/or > or =0.50 D for J0 or J45), and 16.2% for a second type of vector notation (between-eye vector dioptric difference > or =1.41).


CONCLUSIONS
Prevalence of SE anisometropia is similar to that reported for other school-aged populations. However, prevalence of astigmatic anisometropia is higher than that reported for other school-aged populations.
Dobson
Velma
V
Department of Ophthalmology and Vision Science, The University of Arizona, Tucson, AZ 85711, USA. vdobson@eyes.arizona.edu
Harvey
Erin M
EM
Miller
Joseph M
JM
Clifford-Donaldson
Candice E
CE
D000293:Adolescent; D017677:Age Distribution; D015858:Anisometropia / Q000208:ethnology*; D001130:Arizona / Q000453:epidemiology; D001251:Astigmatism / Q000208:ethnology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007198:Indians, North American / Q000706:statistics & numerical data*; D008297:Male; D015995:Prevalence; D012029:Refraction, Ocular; D042262:Retinoscopy; D017678:Sex Distribution