Kemper A, Harris R, Lieu TA, et al. Screening for Visual Impairment in Children Younger than Age 5 Years: A Systematic Evidence Review for the U.S. Preventive Services Task Force [Internet]. Rockville (MD): Agency for Healthcare Research and Quality (US); 2004 May. (Systematic Evidence Reviews, No. 27.)
- Full report
- No journal article available
- No working link to USPSTF Recommendation Statement
Visual impairment is common in children younger than age 5 years. Early detection of visual impairment is thought to lead to better outcomes. New screening technologies, such as photorefractive screening, allow for the screening of very young children.
To review systematically the literature regarding the effectiveness of screening for visual impairment in children younger than age 3 years, and in children 3 years through 5 years of age.
We systematically searched MEDLINE® from 1966 through 1999 to identify studies regarding the prevalence of visual impairment, the effectiveness of treatment, the diagnostic accuracy of the screening tests, and the consequences of treated and untreated visual impairment. We also conducted hand-checks of bibliographies and extensive peer review to identify articles not captured through our main search strategy.
We included prevalence studies if they reflected the general population and evaluated subjects systematically for those conditions for which screening could be useful. We retained diagnostic accuracy studies if they evaluated commercially available tests and reported sensitivity and specificity results based on evaluation against a criterion standard. We included treatment outcome studies if they involved children younger than age 5 years and had a standard measure of visual acuity as an outcome measure. Studies of the consequences of treated or untreated visual impairment were used if the visual impariment was present by at least age 5 years.
A single reviewer examined titles and abstracts of articles and excluded those that clearly did not meet inclusion criteria. This reviewer then examined the full articles of the remaining studies to determine final eligibility.
A single reviewer abstracted the relevant data from the included articles and entered them into a Microsoft Excel spreadsheet.
The prevalence of visual impairment in children 5 years of age and younger is between 7% and 8%. Three percent of children have amblyopia. Few data are available regarding the long-term consequences of untreated amblyopia.
We found no randomized trials of screening. Treating children younger than age years who have cataracts or strabismus may prevent the development of amblyopia. It is unclear whether treating young children with refractive errors associated with amblyopia would prevent the development of amblyopia. Furthermore, a theoretical risk exists that treating refractive errors in children younger than age 3 years may interfere with the normal development of the eye.
Indirect evidence supports the effectiveness of treatment for amblyopia and indicates treatment becomes more difficult with age. The cut-off age at which treatment is no longer effective depends on many factors, including the cause of the amblyopia. In general, treatment seems most effective when initiated before the grade-school years. Treatment for amblyopia may transiently decrease acuity in the nonamblyopic eye.
Treatment of refractive errors not associated with amblyopia is nearly always successful and does not depend upon the age of the child. As with the treatment of refractive errors associated with amblyopia, treating children younger than age 3 years in the circumstance may, at least theoretically, interfere with the normal development of the eye.
Few high-quality data are available regarding the performance of current screening tests. None of these studies was performed in the primary care practice setting by usual caregivers. Few data are available about the long-term consequences of visual impairment in children.
Visual impairment is common in childhood. Although early intervention is important for the prevention or treatment of visual impairment, treatment of certain refractive errors in children younger than age 3 years may interfere with the development of the eye. Few data are available regarding the performance of screening tests in the primary care practice setting.