Abstract
Purpose::
(1) To describe typical refractive development in preschool children, as measured non-cyclopleged with a commercial infrared photorefractor. (2) To evaluate how useful screening for refractive errors might be in a pediatric practise.
Methods::
During the standard regular preventive examinations of all young children in Germany by a pediatrician, 736 children were also measured with the first generation PowerRefractor (made by MCS, Reutlingen, Germany, but no longer available in this version). Of those, 172 were also measured with +3D spectacles to find out whether this would facilitate the detection of hyperopia. Children measured with >2D of hyperopia or astigmatism, >1.5D of anisometropia, or >1D of myopia in the second year of life were referred to an eye care specialist. The actions taken by the eye care specialist were recorded to evaluate the merits of the screening.
Results::
The average non-cycloplegic spherical refractive errors in the right eyes declined about linearly from +0.93D to +0.62D over the first six years (p<0.001) - between 1.5D and 0.5D less hyperopic than in published studies with cycloplegic retinoscopy. As expected, +3D spectacle lenses moved the refractions into the myopic direction (by 2.41D, SD 0.65D), but this shift was not smaller in those children that were measured hyperopic with the PowerRefractor. Negative cylinder magnitudes declined from -0.89D to -0.48D (linear regression: p<0.001). Cylinder axes displayed significant mirror symmetry in both eyes (p<0.001). The average absolute anisometropias (difference of spheres) declined from 0.37 to 0.23D (linear regression: p < 0.001). Of the 736 children, 85 (11.5%) were referred to an eye care specialist. Of these, 52 received spectacles (61.2%), 14 (16.4%) were identified as "at risk" and remained under observation, and 18 (21.2%) were considered "false positive".
Conclusions::
Non-cycloplegic photorefraction provided considerably less hyperopic readings than retinoscopy under cycloplegia. Refractions through binocular +3D lenses did not facilitate the detection of hyperopia. With the referral criteria above, 11.5% of the children was referred to an eye care specialist, but about every 5th was judged "false alarm". This type of screening had some success in identifying children at risk but the number of false negatives remained uncertain.
Keywords: refractive error development • visual development: infancy and childhood • hyperopia