title: Comparison of cycloplegic and noncycloplegic retinoscopy in Chinese pre-school children.
abstract: Twenty-seven Hong Kong Chinese children, aged 3 to 5 1/2 years, were recruited in this study to evaluate the relation between refractive error as measured retinoscopically before and after cycloplegia using cyclopentolate 1%. The noncycloplegic spherical refractive error of these children ranged from -0.75 to +2.50 D and approximately 98% of the Hong Kong pre-school children have a manifest spherical error within this range. The cycloplegic refractive error can be approximated by multiplying the spherical component of the manifest error by 1.45 and adding +0.39 D to the product, while keeping the astigmatic power and axis unchanged. Cyclopentolate 1% requires more time to produce mydriasis and cycloplegia in eyes with heavily pigmented irides; however, its final effect on refractive error is apparently independent of iris pigmentation and depends on the amount of spherical refractive error present.
authors.affiliation: Department of Optometry and Radiography, Hong Kong Polytechnic.
authors.forename: O Y
authors.initials: OY
authors.lastname: Chan
authors.forename: M
authors.initials: M
authors.lastname: Edwards
mesh_terms: D000065:Accommodation, Ocular / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D002681:China; D002924:Ciliary Body / Q000187:drug effects; D003519:Cyclopentolate / Q000008:administration & dosage*; D006801:Humans; D009883:Ophthalmic Solutions; D009907:Optometry / Q000295:instrumentation; D012030:Refractive Errors / Q000503:physiopathology*; D015203:Reproducibility of Results
chemical_list: D009883:Ophthalmic Solutions; D003519:Cyclopentolate