This report may be used, in whole or in part, as the basis for development of clinical practice guidelines and other quality enhancement tools, or a basis for reimbursement and coverage policies. AHRQ or U.S. Department of Health and Human Services endorsement of such derivative products may not be stated or implied. AHRQ is the lead Federal agency charged with supporting research designed to improve the quality of health care, reduce its cost, address patient safety and medical errors, and broaden access to essential services. AHRQ sponsors and conducts research that provides evidence-based information on health care outcomes; quality; and cost, use, and access. The information helps health care decisionmakers—patients and clinicians, health system leaders, and policymakers— make more informed decisions and improve the quality of health care services. Systematic Evidence Review Number 27 Screening for Visual Impairment in Children Younger than Age 5 Years: A Systematic Evidence Review for the U.S. Preventive Services Task Force Prepared for: Agency for Healthcare Research and Quality U.S. Department of Health and Human Services 540 Gaither Road Rockville, MD 20850 http://www.ahrq.gov Contract No. 290-97-0011 Task No. 3 Technical Support of the U.S. Preventive Services Task Force Prepared by: Research Triangle Institute Evidence-based Practice Center 3040 Cornwallis Road P.O. Box 12194 Research Triangle Park, North Carolina 27709 Alex Kemper, MD, MPH, MS Russell Harris, MD, MPH Tracy A. Lieu, MD, MPH Charles J. Homer, MD, MPH B. Lynn Whitener, DrPH, MSLS Date of Pub May 2004 Preface The Agency for Healthcare Research and Quality (AHRQ) sponsors the development of Systematic Evidence Reviews (SERs) through its Evidence-based Practice Program. With guidance from the U.S. Preventive Services Task Force∗ (USPSTF) and input from Federal partners and primary care specialty societies, the Evidence-based Practice Center at the Oregon Health Sciences University systematically review the evidence of the effectiveness of a wide range of clinical preventive services, including screening, counseling, and chemoprevention, in the primary care setting. The SERs—comprehensive reviews of the scientific evidence on the effectiveness of particular clinical preventive services—serve as the foundation for the recommendations of the USPSTF, which provide age- and risk-factor-specific recommendations for the delivery of these services in the primary care setting. Details of the process of identifying and evaluating relevant scientific evidence are described in the “Methods” section of each SER. The SERs document the evidence regarding the benefits, limitations, and cost-effectiveness of a broad range of clinical preventive services and will help further awareness, delivery, and coverage of preventive care as an integral part of quality primary health care. AHRQ also disseminates the SERs on the AHRQ Web site (http://www.ahrq.gov/clinic/uspstfix.htm) and disseminates summaries of the evidence (summaries of the SERs) and recommendations of the USPSTF in print and on the Web. These are available through the AHRQ Web site and through the National Guideline Clearinghouse (http://www.ngc.gov). We welcome written comments on this SER. Comments may be sent to: Director, Center for Practice and Technology Assessment, Agency for Healthcare Research and Quality, 540 Gaither Road, Suite 3000, Rockville, MD 20850. Carolyn Clancy, M.D. Jean Slutsky, P.A., M.S.P.H. Director Acting Director, Center for Practice and Agency for Healthcare Research and Quality Technology Assessment Agency for Healthcare Research and Quality ∗The USPSTF is an independent panel of experts in primary care and prevention first convened by the U.S. Public Health Service in 1984. The USPSTF systematically reviews the evidence on the effectiveness of providing clinical preventive services--including screening, counseling, and chemoprevention--in the primary care setting. AHRQ convened the USPSTF in November 1998 to update existing Task Force recommendations and to address new topics. Acknowledgments This study was developed by the RTI/UNC Evidence-based Practice Center under contract to the Agency for Healthcare Research and Quality (Contract No. 290-97-0011), Rockville, MD. We acknowledge the assistance at AHRQ of Jacqueline Besteman, J.D., M.A., EPC Program Officer; David Atkins, M.D., M.P.H., Director, Clinical Prevention Program and Dana Best, MD, the AHRQ Task Officer. We extend our appreciation as well to RTI-UNC EPC staff, including Kathleen N. Lohr, PhD, co-director of the EPC’s Clinical Prevention Center; Sonya Sutton, BSPH, and Sheila White, of Research Triangle Institute. Request for Reprints Reprints are available from the AHRQ Web site at www.ahrq.gov (click on Preventive Services) and in print through the AHRQ Publications Clearinghouse (call1-800-358-9295). Disclaimer The authors of this article are responsible for its contents, including any clinical or treatment recommendations. No statement in this article should be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services. Structured Abstract Context: 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. Objective: 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. Data Sources: 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. Study Selection: 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 impairment 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. Data Extraction: A single reviewer abstracted the relevant data from the included articles and entered them into a Microsoft Excel spreadsheet. Data Synthesis: 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 this 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. Conclusions: 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. Contents Structured Abstract .................................................................................................................................... v I. Introduction..........................................................................................................................1 Vision Impairment and Screening