Prevalence and etiology of amblyopia of children in Yaoundé (Cameroon), aged 5-15 years

Abstract

To determine the frequency of amblyopia and identify its causes in a population of children aged 5-15 years in Cameroon. This retrospective study examined the files of children aged 5-15 years seen in a private eye clinic in Yaounde from January 2008 through December 2010. The subjects underwent a complete ophthalmic examination including assessment of the best corrected visual acuity on a LogMAR chart, cycloplegic refraction measurements, and an orthoptic examination. The slit-lamp microscope and eye fundus examinations made it possible to rule out organic diseases. Statistical analysis was performed with Epi Info software, version 3.5.3, to analyze the the frequency and laterality of amblyopia according to age, sex, and refractive errors. Twenty-eight of the 314 patients studied had amblyopia, for a frequency of 8.9 % in the study population and 10.3 % in the subjects with ametropia (n = 271). The average age of children with amblyopia was 9.9 + / - 3 years. The frequency of amblyopia was higher among boys, but the difference was not statistically significant (p=0.3679). In order of frequency, the causes were refractive errors, for 93 % (26/28) of the children, and strabismus for 7 % (2/28). Astigmatism was the most frequent cause of ametropic amblyopia. Amblyopia had an anisometropic origin in 43 % (12/28) of cases. It was unilateral in 39.2 % (11/28) and bilateral in 61 % (17/28) of cases, severe in 18 %, moderate in 18 %, and mild in 64 %. Ten percent of the subjects in our series had amblyopia, mainly due to refractive errors. Amblyopia was most frequently bilateral and mild. A systematic ophthalmological examination in childhood could provide early detection and management of refractive errors that cause ocular morbidity.