Ophthalmological data on 4.5- to 7-year-old Danish children

Abstract

Purpose: To report normative data on visual acuity (VA) for near and distance, refraction, ocular alignment, ocular motility and stereo acuity in a cohort of children aged 4.5-7 years.

Methods: A total of 950 children with normal development from the municipality of Roskilde, Denmark, were invited to participate in an ophthalmic cross-sectional population-based survey, of which 445 children in the age of 54-87 months participated with a complete ocular examination including cycloplegia. Visual acuity (VA) was tested using Kay Picture charts and notified in logMAR units.

Results: Mean distance VA was 0.010 logMAR [standard deviation (SD): 0.048] in right eye, and near VA in right eye was 0.012 logMAR (SD: 0.054), with a nonsignificant difference between right and left eye in both parameters (paired t-test, p = 0.15 and p = 0.08, respectively). Amblyopia was found in 12 children (2.7%), mainly related to refractive errors. The mean refractive error of right eye was +1.75 D, and significant hyperopia (greater than +3.0 D) was found in 7.9%. No myopia (greater than or equal to -0.5 D) was found, astigmatism (>1 D) was seen in 4.3%. Manifest strabismus was present in 1.6%, and heterophoria in 4.0%. Reduced or absent stereo acuity was present in 35 children (7.9%) and was related to a reduced VA, refractive error and strabismus.

Conclusion: Ophthalmic data of 445 normally developed children are presented, supplementing previous reported normative data in children. We found a relatively high prevalence of amblyopia and of hyperopia, while myopia was not found, confirming previous studies that myopia is not developing at early age in Danish children.

Keywords: children; convergence; eye motility; population-based study; refractive errors; stereo acuity; strabismus; visual acuity.