Part E. Vision and Hearing Disorders

33.  Screening for Visual Impairment

RECOMMENDATION

Vision screening to detect amblyopia and strabismus is recommended once for all children prior to

entering school, preferably between ages 3 and 4. Clinicians should be alert for signs of ocular

misalignment when examining infants and children. Screening for diminished visual acuity with

Snellen visual acuity chart is recommended for elderly persons. There is insufficient evidence to

recommend for or against screening for diminished visual acuity among other asymptomatic

persons, but recommendations against routine screening may be made on other grounds (see

Clinical Intervention).

Burden of Suffering

Preschool Children.  Undetected vision problems are common in preschool children, with an

estimated prevalence of 5-10%.1 About 2-5% suffer from amblyopia ("lazy eye"; loss of vision

due to disuse) and strabismus (ocular misalignment) which, aside from congenital conditions,

usually develop between infancy and ages 5-7.2-4 In the newborn, risk factors for developing

strabismus or amblyopia include a family history of ocular malformations, anisometropia (a large

difference in refractive power between the two eyes, more than 4 diopters in sphere and/or 2

diopters in astigmatism), congenital cataracts, ocular tumors, premature birth, or birth to a

mother who suffered from infection such as rubella, genital herpes, or  toxoplasmosis during

pregnancy. Since normal vision from birth is necessary for normal binocular development,

failure to detect and treat amblyopia, marked anisometropia, or strabismus at an early age may

result in irreversible visual deficits. Resulting permanent amblyopia and cosmetic defects may

lead to later restrictions in educational and occupational opportunities.5,6 Patients with

amblyopia are at increased risk of blindness from loss of vision in their good eye.6a

School-Aged Children.  Data are limited regarding the prevalence of uncorrected refractive errors

and previously undiagnosed vision problems in elementary school-aged and adolescent children. A

community-based examination of all first- to third-grade children in 1984 found visual acuity of

20/30 or better in the better eye in 94-95% of the schoolchildren; 7%, 9%, and 9% of children

in first, second, and third grades, respectively, had glasses prescribed. Two percent of children

for whom glasses were prescribed were not wearing them.7 Refractive errors, which often

become manifest during school age, rarely carry any serious prognostic implications. Experts

disagree on whether an uncorrected refractive error that would be detected by screening has any

adverse effects on academic performance in school-aged children.7,8

Adolescents and Adults.  Refractive errors are the most common visual disorder in the adolescent

and adult population. In a study of undetected eye disease in a primary care population (94%

African-American), 21% of patients ages 40-59 were diagnosed with an eye disease of which they

were not aware.9 The majority of these cases, however, were not detected by acuity screening

(e.g., glaucoma or diabetic retinopathy), most were mild or previously diagnosed, and few

required immediate treatment. There are no data to determine the incremental benefit of routine

screening of adults to detect early refractive errors compared to waiting for patients to present

with complaints of vision problems.

Elders.  Visual impairment is a common and potentially serious problem among older people.

Personal safety may be compromised; the risk of falling is increased.10 The rate ratio for fatal

car crashes in the elderly is lower in states where vision testing is required for persons over 65

than in states where it is not required.11 While a reduction in visual acuity may be noticed by an

individual, underreporting is common. One small study of patients attending a geriatric day care

center showed that one third had unrecognized severe visual loss.12 Surveys have revealed that up

to 25% of older people are wearing inappropriate visual correction.13 The Baltimore Eye Survey

reported that more than half of the 5,300 persons screened had improved vision after refraction

and appropriate corrective lenses.14 In the Beaver Dam Eye Study, visual acuity with current

correction was worse than 20/40 in 5% of persons aged 65-74, and was worse than 20/40 in

21% of those 75 years of age or older; the proportion with correctable poor acuity was not

reported.15 A 1995 study found that uncorrected vision problems are common among nursing

home residents. Among 499 residents, 17% had bilateral blindness (acuity 20/200) and 19%

had impaired vision (<20/40); a substantial proportion of vision problems in this population

could have been remedied by adequate refractive correction or treatment of cataracts.15a

The most common causes of visual impairment in the elderly include presbyopia, cataract,

age-related macular degeneration (ARMD), and glaucoma (see Chapter 34). In persons over age

75 years, 5% have exudative macular degeneration, and 5% have glaucoma.16-18 The prevalence

of cataract increases with age. In persons aged 55-64 years, the Beaver Dam Eye Study found 33%

with early cataract and 6% with late cataract; in persons over 75 years these prevalences were

37% and 52%.17 The frequency of visually significant cataract is higher in women than in

men.17 The causes of blindness vary by race, with whites being more commonly afflicted with

macular degeneration and blacks having a higher prevalence of untreated cataract and open-angle

glaucoma.19

Accuracy of Screening Tests

Preschool Children.  Despite the importance of early childhood screening for strabismus and

amblyopia, detecting occult visual disorders by screening tests in children under 3 years of age

has generally been unsuccessful. Obstacles to screening include the child's inability to cooperate,

the time required for testing, and inaccuracy of the tests.20,21 Some of the techniques for this age

group, such as preferential looking, grating acuity cards, refractive screening, and photographic

evaluation, have not yet been proven effective.22,23

Screening tests for detecting strabismus and amblyopia in the 3-5-year-old child include simple

inspection, cover test, visual acuity tests, and stereo vision assessment. Although it is widely

recommended,24 reports are not available of sensitivity or specificity of the cover test performed

by primary care providers. Visual acuity tests for children include the Snellen chart, the Landolt

C, the tumbling E, the Allen picture cards, grating cards, and others.25 The specificity of any

acuity test for detecting strabismus or amblyopia is imperfect as other conditions may be the

cause of the diminished acuity. Snellen letters are estimated to have a sensitivity of only 25%-

37%.26 Refractive screening is not a test for strabismus or amblyopia per se, but may be used to

identify amblyogenic risk factors (e.g., anisometropia, or severe hyperopia [farsightedness]).27

The Modified Clinical Technique (MCT) includes retinoscopy, cover testing, quantifying ocular

misalignment, Snellen acuity, color vision assessment, and external observation.28 Preferential

looking (PL) has been substituted for Snellen acuity in the MCT without loss of predictive power

of the MCT but with increase in percentage of young children who were able to complete the test.23

The MCT, despite a high sensitivity and specificity, cannot be used routinely by primary care

physicians for screening because it takes on average about 12 minutes to perform and requires

skills and instrumentation not typically found in this setting.

Stereograms such as the Random Dot E (RDE) have been proposed as more effective than visual

acuity tests in detecting strabismus and amblyopia.25,29 The test, in which the child wears

Polaroid glasses while viewing the test cards, takes about 1 minute. The RDE has an estimated

sensitivity of 54-64%, specificity of 87-90%, positive predictive value of 57%, and negative

predictive value of 93%.30,31

An evaluation of a preschool vision screening program comprising visual inspection, acuity

assessment, and evaluation of stereoacuity, found a combined negative predictive value of 99% for

amblyopia, strabismus, and/or high refractive errors.32 A similar program, evaluated with

limited use of definitive examinations, reported a positive predictive value of 72% for

screening.33 A positive screening test does not ensure adequate follow-up. In one practice-based

study, nearly half of parents of children who had a positive screen were unaware of that result 2

months later; 15% of children referred to a specialist did not make or keep the subsequent

appointment.34

School-Aged Children.  The public school system in most states has taken on the responsibility of

vision screening in school-aged children and making referrals to eye care specialists. In 1992, all

but 12 states had mandatory or regulated screening of elementary school-aged children. Screening

of visual acuity is generally accomplished with standard Snellen vision charts. Although referral

criteria and procedures vary widely, school screening may have a false-positive rate of 30% or

more.35,36

Elders. Asking screening questions about visual function has yielded mixed results when compared

to use of a Snellen acuity chart. The question "Do you have difficulty seeing distant objects?" had

sensitivity of 28% in detecting visual acuity worse than 20/40.37 "(When wearing glasses) Can

you see well enough to recognize a friend across the street?" had sensitivity of 48%.38 A similar

question showed lower sensitivity for visual impairment as part of the HANES 1971-72

survey.39 A brief questionnaire using an additive score formed from three similar questions was

found to have sensitivity of 86% and specificity of 90% for visual acuity worse than 20/40 in a

combined sample of 248 persons aged 45 years and older selected at random from a community

population, and a convenience sample of 118 diabetics from the Wisconsin Epidemiologic Survey of

Diabetic Retinopathy.40

Impaired visual acuity is readily detected by use of a Snellen chart. Cataracts are detectable by

ophthalmoscopy, even by relatively inexperienced health professionals. There are few data on

sensitivity and specificity of these examinations in the primary care setting. Funduscopy may

reveal characteristic changes of ARMD. While these abnormalities are readily recognized by

ophthalmologists and optometrists trained in funduscopy, no studies of the sensitivity of

funduscopy by primary care physicians were found in a computerized literature search.41 Case

reports support the usefulness of the Amsler grid to detect early detachment of the retinal pigment

epithelium at a point when immediate treatment may be beneficial, but compliance with testing is

poor.42,43

Effectiveness of Early Detection

Preschool Vision Problems.  There is fair evidence based on animal models, and case series and

case-control studies in humans, that early detection and treatment of amblyopia and strabismus in

infants and young children improves the prognosis for normal eye development.24,44-49 The

success of intervention may be dependent on age, with increased likelihood of attaining normal or

near-normal vision with earlier detection and treatment; the older the patient, the longer the

duration of treatment needed. In a prospective study of visual acuity screening in matched cohorts

of over 700 preschool children, those who were screened had significantly less visual impairment

than the controls when reexamined 6-12 months later.50

Vision Problems in School-Aged Children, Adolescents, and Nonelderly Adults. There is little

evidence that early detection of refractive errors is associated with important clinical benefits,

compared with testing based on symptoms. A common justification for regular screening in

school-aged children is the concern that undetected vision problems are an important cause of

academic difficulty, but there is no evidence that routine screening has important benefits in

terms of academic performance.51,52

Vision Problems in Elders.  Refractive errors are readily correctable with eye glasses or contact

lenses. Following refraction and correction, 54% of subjects in the Baltimore Eye Survey

improved their visual acuity by at least one line on the Snellen chart and 8% improved by three

lines or more. While the impact on physical and social function of these improvements is

unknown, it has been demonstrated that restoration of vision following cataract surgery leads to

subjective improvements in a variety of vision-related functions, as well as improvements in

objective measures of physical and intellectual function.53

Although ophthalmologists use differing criteria to determine the optimal time to remove

cataracts, a general rule is that surgery should be considered when an otherwise well patient feels

that there is a significant impairment to daily life caused by the vision loss. While there are

theoretical reasons to believe that earlier referral to an ophthalmologist is desirable for

assessment of retinal disease prior to obliteration of the view of the fundus by advancing cataract,

in practice most individuals will complain of visual loss and be treated before this occurs.

Randomized clinical trials have shown a beneficial effect of argon laser photocoagulation of

choroidal neovascular membranes in selected cases of ARMD.54 Controlled trials with other

wavelengths of light (e.g., krypton) are currently underway. Medical therapy for ARMD, with zinc

supplements or interferon, has been reported as case series, but it has not yet been evaluated

more rigorously.55,56

Recommendations of Other Groups

The Canadian Task Force on the Periodic Health Examination (CTF)57 concluded that there is fair

evidence to recommend visual acuity testing of preschool children. The American Academy of

Ophthalmology (AAO),58 American Optometric Association,59 American Academy of Pediatrics

(AAP),60 and Bright Futures61 each recommend examining newborns and infants for ocular

problems and screening visual acuity and ocular alignment at age 3 or 4 in children, and every 1-

2 years thereafter through adolescence. New guidelines for vision screening in children, outlining

which tests to use and criteria for referral, have been developed by the AAP Section on

Ophthalmology, in conjunction with the AAO and the American Association for Pediatric

Ophthalmology and Strabismus.62 The American Academy of Family Physicians (AAFP)

recommends that all children be screened for eye and vision abnormalities at 3-4 years of age and

that clinicians remain alert for vision problems throughout childhood and adolescence.63

Periodic comprehensive eye examinations including acuity testing are recommended for all adults

by the American Optometric Association and by Prevent Blindness America (formerly National

Society to Prevent Blindness)59 and for adults over age 40 by the American Academy of

Ophthalmology.65 The CTF41 and the AAFP63 advise routine screening of visual acuity only for

individuals age 65 and over. AAFP recommendations on vision screening are currently under

review.

Discussion

No prospective trial has directly assessed the benefits of routine preschool vision screening, but

animal models and observational studies provide fair evidence that earlier detection and treatment

improves the outcomes in children with strabismus and amblyopia. Screening and early referral

is recommended for infants and preschool children in the primary care setting. The optimal age for

screening cannot be determined from direct evidence. The recommendation to screen at ages 3-4

years is based primarily on expert opinion, and reflects a compromise between the inability of

younger children to cooperate fully with screening and the goal to detect and treat the conditions as

early as possible.

Screening older children, adolescents, and adults is less likely to detect vision problems that

require early intervention. Although routine screening in asymptomatic persons may detect some

persons with early refractive errors, these are readily corrected when patients become

symptomatic. It is not certain that the incremental benefit of early detection (compared to

evaluation when patients complain of change in vision) is sufficient to justify the costs and

inconvenience of routine testing. Any patient with ocular symptoms, however, should be advised to

see an eye care specialist.

Vision problems are more prevalent in persons over 65, and they are more likely to lead to

serious consequences such as accidental injuries. Questioning elderly patients about vision

problems is less sensitive than directly assessing visual acuity. Although the effect on functional

outcomes of periodic screening with Snellen chart acuity testing in the elderly has not been

directly assessed, there is fair evidence that routine screening leads to improvements in measured

acuity, and there is little chance of serious harm from screening. The role of routine screening

with funduscopy by the primary care provider is less certain. Funduscopy is likely to be more

sensitive than acuity testing for detecting persons with exudative ARMD, especially those with

early disease, who may benefit from photocoagulation therapy. The sensitivity and specificity of

funduscopy by primary care providers for ARMD is unknown, however.

CLINICAL INTERVENTION

Vision screening for amblyopia and strabismus is recommended for all children once before

entering school, preferably between ages 3 and 4 years ("B" recommendation). Clinicians should

be alert for signs of ocular misalignment when examining all infants and children. Stereoacuity

testing may be more effective than visual acuity testing in detecting these conditions.

There is insufficient evidence to recommend for or against routine screening for diminished visual

acuity among asymptomatic schoolchildren and nonelderly adults ("C" recommendation).

Recommendations against such screening may be made on other grounds, including the

inconvenience and cost of routine screening, and the fact that refractive errors can be readily

corrected when they produce symptoms.

Routine vision screening with Snellen acuity testing is recommended for elderly persons  ("B"

recommendation). The optimal frequency for screening is not known and is left to clinical

discretion. Selected questions about vision may also be helpful in detecting vision problems in

elderly persons, but they do not appear as sensitive or specific as direct assessment of acuity.

There is insufficient evidence to recommend for or against routine screening with ophthalmoscopy

by the primary care physician in asymptomatic elderly patients ("C" recommendation).

The draft update of this chapter was prepared for the U.S. Preventive Services Task Force by

Joseph N. Blustein, MD, MS, and Dennis Fryback, PhD, based in part on materials prepared for

the Canadian Task Force on the Periodic Health Examination by Christopher Patterson, MD, FRCP,

and John W. Feightner, MD, MSc, FCFP.

REFERENCES

	1. National Center for Health Statistics. Refraction status and motility defects of persons

4-74 years, U.S. 1971-72: Vital health statistics, Series 11, 1978.

	2. Ehrlich MI, Reinecke RD, Simons K. Preschool vision screening for amblyopia and

strabismus: programs, methods, guidelines. Surv Ophthalmol 1983;28:145-163.

	3. Cross AW. Health screening in schools: part I. J Pediatr 1985;107:487-494.

	4. Thompson JR, Woodruff G, Hiscox FA, Strong N, Minshull C. The incidence and

prevalence of amblyopia detected in childhood. Public Health 1991;105:455-462.

	5. Campbell LR, Charney E. Factors associated with delay in diagnosis of childhood

amblyopia. Pediatrics 1991;87:178-185.

	6. Magramm I. Amblyopia: etiology, detection, and treatment. Pediatr Rev 1992;13:7-14.

	6a. Woodruff G. Amblyopia: could we do better? BMJ 1995;310:1153-1154.

	7. Helveston EM, Weber JC, Miller K, et al. Visual function and academic performance. Am

J Ophthalmol 1985;99:346-355.

	8. Rosner J, Rosner J. Comparison of visual characteristics in children with and without

learning difficulties. Am J Optom Physiol Optics 1987;84:531-533.

	9. Wang F, Ford D, Tielsch JM, et al. Undetected eye disease in a primary care population.

Arch Intern Med 1994;154:1821-1828.

	10. Hindmarsh JA, Estes EH. Falls in older persons: etiology and interventions. In:

Goldbloom RB, Lawrence RS, eds. Preventing disease. Beyond the rhetoric. New York:

Springer-Verlag, 1990.

	11. Nelson DE, Sacks JJ, Chorba TI. Required vision testing for older drivers. N Engl J Med

1992;326: 1784-1785.

	12. McMurdo ME, Baines PS. The detection of visual disability in the elderly. Health Bull

1988;46: 327-329.

	13. Stults BM. Preventive health care for the elderly. West J Med 1984;141:832-845.

	14. Tielsch JM, Sommer A, Witt K, Katz J, Royall RM. Blindness and visual impairment in

an American urban population. The Baltimore Eye Survey. Arch Ophthalmol 1990;108:286-290.

	15. Klein R, Klein BE, Linton KL, De MD. The Beaver Dam eye study: visual acuity.

Ophthalmology 1991;98:1310-1315.

	15a. Tielsch JM, Javitt JC, Coleman A, et al. The prevalence of blindness and visual

impairment among nursing home residents in Baltimore. N Engl J Med 1995;332:1205-1209.

	16. Klein R, Klein BE, Linton KL. Prevalence of age-related maculopathy. The Beaver Dam

eye study. Ophthalmology 1992;99:933-943.

	17. Klein BE, Klein R, Linton KL. Prevalence of age-related lens opacities in a population.

The Beaver Dam eye study. Ophthalmology 1992;99:546-552.

	18. Klein BE, Klein R, Sponsel WE, et al. Prevalence of glaucoma. The Beaver Dam eye

study. Ophthalmology 1992;99:1499-1504.

	19. Sommer A, Tielsch JM, Katz J, et al. Racial differences in the cause-specific

prevalence of blindness in East Baltimore. N Engl J Med 1991;325:1412-1417.

	20. Jacobson SG, Mohindra I, Held R. Visual acuity of infants with ocular disease. Am J

Ophthalmol 1982;93:198-209.

	21. Hall SM, Pugh AG, Hall DMB. Vision screening in the under-5s. BMJ

1982;285:1096-1098.

	22. Jarvis SN, Tamhne RC, Thompson L, Francis PM, Anderson J, Colver AF. Preschool

vision screening. Arch Dis Child 1991;66:288-294.

	23. Schmidt PP. Effectiveness of vision-screening in pre-school populations with

preferential-looking cards used for assessment of visual acuity. Optom Vision Sci 1991;68:210-

219.

	24. Day S, Eggers H, Gammon JA, Spivey BE. Early strabismus/amblyopia screening.

Patient Care 1990;24:83-105.

	25. Fern KD, Manny RE. Visual acuity of the preschool child: a review. Am J Optom Physiol

Optics 1986; 63:319-345.

	26. Lieberman S, Cohen AH, Stolzberg M, Ritty JM. Validation study of the New York State

Optometric Association (NYSOA) vision screening battery. Am J Optom Physiol Optics

1985;62:165-168.

	27. Sjostrand J, Abrahamsson M. Risk factors in amblyopia. Eye 1990;4:787-793.

	28. Peters HB. The Orinda study. Am J Optom Physiol Optics 1984;61:361-363.

	29. Ruttum MS, Bence SM, Alcorn D. Stereopsis testing in a preschool vision screening

program. J Pediatr Ophthalmol Strabismus 1986;23:298-302.

	30. Hammond RS, Schmidt PP. A Random Dot E stereogram for the vision screening of

children. Arch Ophthalmol 1986;104:54-60.

	31. Ruttum MS, Nelson DB. Stereopsis testing to reduce overreferral in preschool vision

screening. J Pediatr Ophthalmol Strabismus 1991;28:131-133.

	32. De Becker I, MacPherson HJ, LaRoche GR, et al. Negative predictive value of a

population-based preschool vision screening program. Ophthalmology 1992;99:998-1003.

	33. MacPherson H, Braunstein J, LaRoche GR. Utilizing basic screening principles in the

design and evaluation of vision screening programs. Am Orthopt J 1991;41:110-121.

	34. Wasserman RC, Croft CA, Brotherton SE. Preschool vision screening in pediatric

practice: a study from the Pediatric Research in Office Settings (PROS) Network. American

Academy of Pediatrics [published erratum appears in Pediatrics 1992;90:1001]. Pediatrics

1992;89:834-838.

	35. Appelboom TM. A history of vision screening. J School Health 1985;55:138-141.

	36. Romano PE. Summary and conclusions. Symposium on preschool/school vision and eye

screening: current techniques and future trends. Am Orthop J 1988;38:73-80.

	37. Stone DH, Shannon DJ. Screening for impaired visual acuity in middle age in general

practice. BMJ 1978;2:859-861.

	38. Haase KW, Bryant EE. Development of a scale designed to measure functional distance

vision loss using an interview technique. Proc Am Stat Assoc 1973;(SS):274-279.

	39. Hiller R, Krueger DE. Validity of a survey question as a measure of visual acuity

impairment. Am J Public Health 1983;73:93-96.

	40. Fryback DG, Martin PA, Klein R, Klein BEK. Short questionnaires about visual function

to proxy for measured best-corrected visual acuity. Invest Ophthalmol Visual Sci 1993;34:1422.

	41. Canadian Task Force on the Periodic Health Examination. Canadian guide to clinical

preventive health care. Ottawa: Canada Communication Group, 1994:932-942.

	42. Fine SL. Early detection of extrafoveal neovascular membranes by daily central field

evaluation. Ophthalmology 1985;92:603-609.

	43. Fine AM, Elman MJ, Ebert JE, Prestia PA, Starr JS, Fine SL. Earliest symptoms

caused by neovascular membranes in the macula. Arch Ophthalmol 1986;104:513-514.

	44. Epelbaum M, Milleret C, Buisseret P, Dufier JL. The sensitive period for strabismic

amblyopia in humans. Ophthalmology 1993;100:323-327.

	45. Lithander J, Sjostrand J. Anisometropic and strabismic amblyopia in the age group 2

years and above: a prospective study of the results of treatment. Br J Ophthalmol 1991;75:111-

116.

	46. Hiscox F, Strong N, Thompson JR, Minshull C, Woodruff G. Occlusion for amblyopia: a

comprehensive survey of outcome. Eye 1992;6:300-304.

	47. Levartovsky S, Gottesman N, Shimshoni M, Oliver M. Factors affecting long-term

results of successfully treated amblyopia: age at beginning of treatment and age at cessation of

monitoring. J Pediatr Ophthalmol Strabismus 1992;29:219-223.

	48. Rutstein RP, Fuhr PS. Efficacy and stability of amblyopia therapy. Optom Vision Sci

1992;69:747-754.

	49. Rubin SE, Nelson LB. Amblyopia. Diagnosis and management. Pediatr Clin North Am

1993;40: 727-735.

	50. Feldman W, Milner RA, Sackett B, Gilbert S. Effects of preschool screening for vision

and hearing on prevalence of vision and hearing problems 6-12 months later. Lancet

1980;2:1014-1016.

	51. Hulme C. The implausibility of low-level visual deficits as a cause of children's

reading difficulties. Cogn Neuropsychol 1988;5:369-374.

	52. Lovegrove W, Martin F, Slaghuis W. A theoretical and experimental case for a visual

deficit in specific reading disability. Cogn Neuropsychol 1986;3:225-267.

	53. Applegate WB, Miller ST, Elam JT, Freeman JM, Wood TO, Gettlefinger TC. Impact of

cataract surgery with lens implantation on vision and physical function in elderly patients. JAMA

1987;257:1064-1066.

	54. Argon laser photocoagulation for senile macular degeneration. Results of a randomized

clinical trial. Arch Ophthalmol 1982;100:912-918.

	55. Newsome DA, Swartz M, Leone NC, Elston RC, Miller E. Oral zinc in macular

degeneration. Arch Ophthalmol 1988;106:192-198.

	56. Fung WE. Interferon alpha 2a for treatment of age-related macular degeneration

[letter]. Am J Ophthalmol 1991; 112:349-350.

	57. Canadian Task Force on the Periodic Health Examination. Canadian guide to clinical

preventive care. Ottawa: Canada Communication Group, 1994:298-304.

	58. American Academy of Ophthalmology. Preferred practice pattern: comprehensive

pediatric eye evaluation. San Francisco: American Academy of Ophthalmology, 1992.

	59. American Optometric Association. Recommendations for regular optometric care. St.

Louis, MO: American Optometric Association, 1994.

	60. American Academy of Pediatrics, Committee on Practice and Ambulatory Medicine.

Recommendations for preventive pediatric health care. Pediatrics 1995;96:373-374.

	61. Green M, ed. Bright Futures: guidelines for health supervision of infants, children and

adolescents. Arlington VA: National Center for Education in Maternal and Child Health, 1994.

	62. AAP Policy Statement: proposed vision screening guidelines. AAP News, vol 11 no 1.

Elk Grove Village, IL: American Academy of Pediatrics, 1995.

	63. American Academy of Family Physicians. Age charts for periodic health examination.

Kansas City, MO: American Academy of Family Physicians, 1994. (Reprint no. 510.)