Canadian Task Force on Preventive Health Care

Routine Preschool Screening for Visual and Hearing Problems

Prepared by John W. Feightner, MD, MSc, FCFP, Department of Family Medicine, The University of Western Ontario

Objective
To make recommendations for routine screening for visual deficits and hearing impairments in asymptomatic Canadian preschool children. These recommendations specifically refer to care given during periodic health examinations (PHEs) in primary care settings and are for use by health professionals and health care planners.

Burden of Suffering

Visual Defects
On the basis of data from two Ontario communities, the prevalence rate of visual deficits in the preschool population is estimated to be 10% to 15%. Estimates for amblyopia range from 1.2% to 5.6% with similar estimates for strabismus. The prevalence of combined amblyopia and strabismus is estimated to be in the region of 5%.

Hearing Deficits
Hearing problems in preschool children are best divided into short-term, transient problems that resolve and persistent problems. The latter category is composed primarily of persistent middle ear effusion and sensorineural deficits. The prevalence of short-term problems is approximately 15% while for persistent problems it is closer to 3%.

Options
Visual charts are used to assess visual acuity. Refractive errors can be corrected with eye glasses. Impairments can be ascertained using the whisper test, pure tone audiometry, mobility of the tympanic membrane, and acoustic reflexometry. Treatment options include ventilation tubes for preschool children with recurrent otitis media.

Outcomes
Sensitivity, specificity, and positive and negative predictive values for the visual and hearing tests. Treatment outcomes include improvement in vision and hearing and adverse effects of language development delays.

Evidence
MEDLINE was searched up to March 1993 using the keywords hearing disorders; vision disorders; child, preschool; mass screening; guideline; and Canada.

Values
The 13-member Task Force of experts in family medicine, geriatric medicine, pediatrics, psychiatry and epidemiology used an evidence-based method for evaluating the effectiveness of preventive health care interventions. Recommendations were not based on cost-effectiveness of options. Patient preferences were not discussed.

Background papers providing critical appraisal of the evidence and tentative recommendations prepared by the chapter author were pre-circulated to the members. Evidence for this topic was presented and deliberated upon in 1- to 2-day meetings, 2 to 3 times per year from January 1993 to June 1993. Consensus was reached on final recommendations.

Benefits, Harms, and Costs
A combined program of visual inspection, assessment of visual acuity, and evaluation of steroacuity had a negative predictive value of 98.7% for amblyopia, strabismus, and/or high refractive errors. A similar program had a positive predictive value of 72%. A Swedish study assessing monocular visual acuity, steroacuity, and use of a cover test found a positive predictive value of 84% for all visual acuity problems with 43% for visual acuity problems that required treatment. Eye glasses effectively treat refractive errors; treatment for amblyopia is more controversial and inconclusive. A cohort study found that 6 to 12 months after screening, screened children had 50% fewer vision problems and 75% fewer severe vision difficulties than did unscreened children.

For hearing difficulties, 2 cohort studies using 2 different criteria sets found tympanometry had a sensitivity and specificity of 48% and 89%, and 78% and 68% respectively. One small study found no differences in language development when children were given ventilation tubes after recurrent otitis media. One cohort study found no differences in hearing deficits between 2 groups, 1 of which had screening and the other who did not have routine hearing screening. Another cohort study found that < 0.3% of the population had hearing deficits.

Recommendations
Recommendation grade [A, B, C, D, E] and level of evidence [I, II-1, II-2, II-3, III] are indicated after each recommendation. Citations in support of individual recommendations are identified in the guideline text.

There is fair evidence to include visual acuity testing for visual deficits in the PHE of preschool children [B, II-2].
There is fair evidence to exclude history taking and clinical examination (pure tome audiometry, tympanometry, acoustic reflexometry) to detect hearing impairment in the PHE of preschool children [D, II-1, II-2].

Validation
This report was externally peer reviewed. The United States Preventive Services Task Force and the American Academy of Pediatrics recommend all children be tested for amblyopia and strabismus once before entering schools (3 to 4 years of age); routine vision acuity testing is not recommended. The American Academy of Ophthalmology, the American Academy of Pediatrics, and the American Association of Pediatric Ophthalmology and Strabismus recommends that all children be given eye and vision screening at birth and 6 months, 3 years, and 5 years. The American Academy of Family Physicians states that it has insufficient evidence to evaluate routine universal screening in children. The American Academy of Pediatrics recommends pure audiometry screening at 4 and 5 years of age. The American Speech and Language Hearing Association recommends routine annual pure tone audiometry for children from 3 to 10 years of age.

Sponsors
The Canadian Task Force on Preventive Health Care developed this guideline with funding from Health Canada.

Source Document
Feightner, J.W. Routine preschool screening for visual and hearing problems. In: Canadian Task Force on the Periodic Health Examination. Canadian Guide to Clinical Preventive Health Care. Ottawa: Health Canada, 1994; 298-304.