Nearly 1 in 4 children aged 5 to 15 years presenting to a pediatric eye clinic in South Ethiopia have amblyopia, according to research published in Clinical Optometry. Among these patients, anisometropia has been identified as the most common cause.
Researchers included 202 children (age range, 5-15 years; 51.5% boys) in the cross sectional analysis. Patients underwent visual acuity assessment, slit lamp evaluation, cycloplegic refraction, cover test, and dilated fundus examination. The primary objective was to establish a profile of amblyopia for patients aged 5 to 15 years.
Overall, researchers identified amblyopia in 23.8% of patients. A majority of these participants were within the age range of 5 to 9 years (55.4%). When stratified by age, children aged 5-9 years (n=112) had a higher prevalence of amblyopia compared with children aged 10-13 years (n=90; 27.67% vs 18.88%).
Anisometropia was identified as the most common cause of amblyopia (31.25%). Other causes included meridional (20.83%), mixed (16.67%), isometropic (12.5%), sensory deprivational (10.42%), and strabismic (8.33%) amblyopia.
The researchers acknowledge conflicting results with other investigations revealing strabismus as the most common cause of amblyopia and attribute these findings to differences in source population. However, they state that other studies confirm uncorrected refractive error as a cause of visual impairment.
“Anisometropia causes amblyopia due to the retina of the more ametropic eye failing to get a clear image and stimuli for accommodative effort,” according to the investigators. “Whereas, the image formed on the retina of the good eye is focused, clear and sharp.”
Study limitations include a single center design and failure to consider the refractive correction adaptation period for refractive amblyopia diagnosis.
Gebru EA, Alem KD, G/Silassie MG. Profile of amblyopia among children aged from 5 to 15 years at Hawassa University Comprehensive Specialized Hospital Pediatric Eye Clinic, South Ethiopia, 2020/21. Clin Optom. 2022;14:149-157. doi:10.2147/OPTO.S372001