The prevalence of anisometropia, amblyopia and strabismus in schoolchildren of Shiraz, Iran.
OBJECTIVE
To determine the prevalence of amblyopia, anisometropia, and strabismus in schoolchildren of Shiraz, Iran.


METHODS
A random cluster sampling was used in a cross-sectional study on schoolchildren in Shiraz. Cycloplegic refraction was performed in elementary and middle school children and high school students had non-cylcoplegic refraction. Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were recorded for each participant. Anisometropia was defined as spherical equivalent (SE) refraction difference 1.00D or more between two eyes. Amblyopia was distinguished as a reduction of BCVA to 20/30 or less in one eye or 2-line interocular optotype acuity differences in the absence of pathological causes. Cover test was performed for investigating of strabismus.


RESULTS
Mean age of 2638 schoolchildren was 12.5 years (response rate = 86.06%). Prevalence of anisometropia was 2.31% (95% confidence interval [CI], 1.45 to 3.16). 2.29% of schoolchildren (95% CI, 1.46 to 3.14) were amblyopic. The prevalence of amblyopia in boys and girls was 2.32% and 2.26%, respectively (p = 0.945). Anisometropic amblyopia was found in 58.1% of the amblyopic subjects. The strabismus prevalence was 2.02% (95% CI, 1.18 to 2.85). The prevalence of exotropia and esotropia was 1.30% and 0.59%, respectively.


CONCLUSIONS
Results of this study showed that the prevalence of anisometropia, amblyopia, and strabismus are in the mid range. The etiology of amblyopia was often refractive, mostly astigmatic, and non-strabismic. Exotropia prevalence increased with age and was the most common strabismus type.
Yekta
AbbasAli
A
Department of Optometry, Mashhad University of Medical Sciences, Mashhad, Iran.
Fotouhi
Akbar
A
Hashemi
Hassan
H
Dehghani
Cirous
C
Ostadimoghaddam
Hadi
H
Heravian
Javad
J
Derakhshan
Akbar
A
Yekta
Reihaneh
R
Rezvan
Farhad
F
Behnia
Mehdi
M
Khabazkhoob
Mehdi
M
D000293:Adolescent; D000550:Amblyopia / Q000175:diagnosis / Q000453:epidemiology*; D015858:Anisometropia / Q000175:diagnosis / Q000453:epidemiology*; D002648:Child; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D015995:Prevalence; D013285:Strabismus / Q000175:diagnosis / Q000453:epidemiology*; D015351:Vision Screening; D014792:Visual Acuity