Abstract
Purpose:
To describe the prevalence of eye disorders in 6 year old children of a multi ethnic cohort in an urban area in the Netherlands. The study is designed to identify early environmental and genetic risk factors and causal pathways leading to abnormal growth and developmental disorders.
Methods:
In total, n = 9,778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study, and n= 6690 children were available for analysis. Data collection in mothers, fathers and children aged 5-6 yrs included questionnaires, detailed physical examinations, behavioural observations, and ascertainment of biological samples. Detailed hands-on ophthalmological assessments were performed in a research center and included LogMAR visual acuity with Lea charts. Children with LogMAR acuity >0.1 and those receiving ophthalmic care were examined by a clinical ophthalmologist who measured cycloplegic refraction and performed retinoscopy. All ophthalmic data obtained from the medical records were itemized according to ICD-9 codes 360-389 and a national strabismus coding system.
Results:
Mean age of the children was 6.1 (SD ±0.5) years. Of those, 610 (9.1%) already received ophthalmological care, and 353 (5.3%) children had a newly detected visual acuity >0.1 LogMAR. Presenting visual acuity in one eye worse than 0.1 was found in n=546 children; a visual acuity worse than 0.1 in both eyes was found in n=227 children. Residual amblyopia of VA ≥0.3 was present in n=19 (0.3%) children. Refractive errors were the cause of visual acuity deficit in n=469 (7%) children, including hyperopia >+2.0 in n=267 (4%) children and myopia ≤ -0,5 in n=157 (2.3%). Manifest strabismus was present in n=110 (1,6%) of which 55 (0,8%) was accommodative esotropia. 45 children required ophthalmological care for other reasons: lacrimal duct stenosis (n=6, 0.1%), congenital ptosis (n=6, 0.1%) and allergic conjunctivitis (n=4, 0.06%). Another n=21 had received more rare diagnoses such as shaken baby syndrome or congenital cataract.
Conclusions:
In this pre-screened population of West European children, only 19 children had a residual severe amblyopia. Nevertheless, 227 children (3.4%) were newly detected with a presenting visual acuity of less than 0.1 LogMAR in both eyes. In these children, refractive errors were the most important causes of visual impairment, followed by strabismus.