PubMed HealthSearch

SEARCH · PubMed Health

Results for “Vision Screening”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

The future of vision screening.

The future of vision screening is presently receiving heated debate. Recent federal legislative activity in the area of comprehensive health planning has caused renewed interest in vision screening. Optometric recommendations supported at various governmental levels call for the development of standards for comprehensive vision screening of school children on a national scale. This paper attempts to review the philosophy and justification for school vision screening and to bring the readers up to date on related governmental activity. The question of adequate manpower to implement a nationwide vision screening program is discussed, and an argument is developed for preparing school nurse practitioners to assume an expanded role in comprehensive vision screening.

Adolescent

Negative predictive value of a population-based preschool vision screening program.

BACKGROUND: The Enhanced Vision Screening Program is a population-based vision screening program that has, at present, examined 59,782 children. Its main goal is to detect amblyopia, strabismus, and high refractive errors. An average of 11,910 4 1/2- to 5 1/2-year-old children are screened yearly. The current study determines the negative predictive value of the screening program: For a subject having passed the vision screening test, what is the probability of not having amblyopia, strabismus, or high refractive errors? METHODS: Of the 11,734 subjects who passed the vision screening, 200 were randomly chosen to undergo a strictly defined gold standard examination by an orthoptist and an ophthalmologist. RESULTS: Of the 200 randomly chosen subjects, 157 underwent the gold standard evaluation. The negative predictive value of the Enhanced Vision Screening Program was 97.6% for any potentially vision-threatening ocular condition. It was 98.7% if we considered only the visually significant ocular problems that the test was designed to detect. CONCLUSION: Because the negative predictive value of the Enhanced Vision Screening Program is not 100%, some children with amblyopia, strabismus, or refractive errors are missed. Occasionally, a rare, potentially vision-threatening condition may go undetected. Parents should be made aware of this when they receive the results of the vision screening.

Child

Effectiveness of vision-screening in pre-school populations with preferential-looking cards used for assessment of visual acuity.

Screening the vision of pre-school populations has been suggested as a way to assure early identification of vision problems as well as early intervention, thereby enabling normal development of the visual system and learning process. In a masked investigation, 119 pre-school children enrolled in Project Headstart with a mean age of 3.51 years (range 3 to 5 years) had their vision screened using the Modified Clinical Technique (MCT). Monocular visual acuities in this population were determined using preferential-looking (PL) cards. Visual acuity assessment of young children in screening settings is at best a challenge; yet, all 119 children were able to complete monocular acuity assessments on each eye. Acuities for nonreferrals (individuals who passed the screening) were significantly better than for referrals (individuals who failed the screening) at the 0.0167 level using a two-tailed Fisher's Exact Test with the Bonferroni Method for multiple comparisons. The effectivity of the screening technique as determined by phi-coefficient remained highest (phi = +0.94) with the visual acuity referral criterion set at 6/12 (20/40) or less either eye and/or greater than or equal to a 2-octave difference between the eyes. The resultant referral rate (17.6%) was higher than that predicted by extrapolation from the Orinda Study for this age group (12.3%) but expected because of the different socioeconomic group. PL cards enabled monocular visual acuity measurement on 100% of the children tested and measurably increased the effectiveness of the screening procedure.

Child, Preschool

Preschool vision screening.

Although a good case for preschool screening for vision defects can be made there is very little evidence that existing programmes are effective in practice. A comparative trial of three different methods of preschool vision screening is described. Some 7000 children initially aged 5 months (younger cohorts) and 30 months (older cohorts) in three matched areas entered the trial during 1987. During 18 months of follow up new visual and ocular defects among these children were ascertained through ophthalmology outpatients and from optician records. Screening at 35 months by an orthoptist based in the community is superior to conventional health visitor surveillance at 30 months and to an agreed programme of primary care screening for squint at 30-36 months as judged by screening sensitivity (100% v 50% v 50%) and the incidence of treated target conditions (17 v 3 v 5 per 1000 person years). A notable feature in the area served by the orthoptist is that 13 children received treatment for straight eyed visual acuity loss from among 1000 children whereas there were no such cases among 2500 in the comparison areas. In the younger cohorts (that is, screening at age 5-9 months) all three programmes showed equally poor results, only one of the eight treated target conditions arising from all 3500 younger children being screen detected.

Amblyopia

Visual disorders in 7-year-old children with and without previous vision screening.

An analysis of visual defects among 310 children referred from a vision screening of 2 178 7-year-old children revealed a 50% frequency of significant eye defects among the referrals (7% of screened children). Of the screened children, one group (1 530 children) had previous visual screening three years earlier. The other group (648 children) had no previous vision screening until the age of seven. A comparison between the two groups showed that the risk of finding a new significant eye disorder in a school entrant was more than 6 times greater for a child who was not examined in his preschool years, and the risk of finding an amblyopic child was more than 10 times greater. The results do indicate the need for continuation of the present vision screening program of pre-school children.

Astigmatism

The True Daylight Illuminator (TDI): a less expensive source of illumination for color vision screening.

This experiment was designed to examine the feasibility of using the True Daylight Illuminator (TDI) as an illumination option for conducting color vision screening with the Ishihara Test(s). The MacBeth Easel Lamp was designed to provide proper illumination for performing color vision screening with a variety of pseudoisochromatic (PIC) plate tests including the Ishihara. However, over the years, the MacBeth Lamp has become so expensive that many smaller programs cannot afford to purchase one. This problem has promoted the use of alternate light sources that have had a deleterious effect on test results and in some instances contributed to job discrimination. Recently the MacBeth Division of the Kollmorgan Corporation discontinued the manufacture of the MacBeth Lamp due to lack of demand. Thus, it is important to find an inexpensive illumination option for conducting color vision screening. Two groups of subjects were used to compare test results for the 24-plate edition of the Ishihara Test using both the MacBeth Lamp and the True Daylight Illuminator. The first group contained 45 subjects with inherited color defective vision. The second group was made up of 30 color normals. The Nagel anomaloscope was used to confirm the color vision status of the subjects in both groups. Statistics to test the significance of differences between group means clearly demonstrated that there were no significant differences between the mean error scores of the two groups for these two pieces of equipment. Thus, it was concluded that the TDI can be used in lieu of the MacBeth Easel Lamp for screening color vision with the Ishihara test.

Adolescent

Vision screening of illiterate populations.

To assess the amount of reduced vision in a population is an important public health matter, especially in areas where blinding diseases are endemic. Testing visual acuity is, however, a complex problem when a major part of the population is illiterate. The best-known test of vision is the E-test, but this produces the problem of untestability in illiterate populations.The introduction of the Sjögren hand-test as an alternative to the E-test for vision screening of unselected illiterate populations in West Africa resulted in a highly significant reduction of untestability. For certain vision levels it is possible to correlate the results of the hand-test directly with those of the E-test. The hand-test is less well defined than the E-test, but has important advantages for the purpose of vision screening of illiterate populations.

Adolescent

Preschool vision screening in pediatric practice: a study from the Pediatric Research in Office Settings (PROS) Network. American Academy of Pediatrics.

In this cross-sectional study, the vision-screening process is described for 8417 children aged 3 to 5 seen for health supervision in a group of 102 pediatric practices in 23 states and Puerto Rico. Three hundred forty children who failed screening (63% of those who failed) were followed up 2 months after initial screening. The sample was 52% male, 86% white, 9% black, 3% Hispanic, and 1% Asian. Vision screening was attempted on 66% of children overall. Pediatricians' reasons for not screening were "not routine" (44%), "too young" (40%), and "screening done previously" (17%). Younger children were less likely to be screened than older children (39% of those aged 3), and Hispanics were less likely to be screened than other ethnic groups (P less than .001). Thirty-three percent of children received no screening for latent strabismus. Two months later, 50% of parents whose child had failed a vision test were unaware of this fact on questionnaire follow-up. Eighty-five percent of children referred to an eye specialist had made or kept an appointment. It is concluded that pediatricians need to increase vision screening among younger preschool children and communicate more effectively to parents the results of screening failure.

Amblyopia

Vision screening project--Eilat, Israel.

The author relates his experience in developing and conducting a vision screening program for 1,522 children between age one to six of Eilat, Israel. He describes a method similar to the Modified Clinical Technique which he adapted to the specific circumstances and devised a simplified two-minute procedure which proved very effective in use. The author clearly demonstrates the need and advantage of a professionally conducted program with cooperation of the Yosepthal Hospital, the public health nurses and the teachers of the Eilat school system. The results indicate a low overall referral rate of 7-1/2%, probably due to the early and careful attention most children receive. His conclusions support the importance of a vision screening program and substantiate the value of a Modified Clinical Screening procedure.

Child

Vision screening in children tested at 7, 11, and 16 years.

Distant vision screenings of a national sample of children were performed at the ages of 7, 11, and 16. Many children with normal vision at one screening showed defects at later screenings, and altogether 18% of children with normal vision at the age of 7 had defects by the time they were 16. Twelve per cent of those with normal vision at 7 and 11 had developed a visual defect by the age of 16. Apparent improvements between screenings probably resulted largely from technical difficulties inherent in testing young children. The results clearly indicate the importance of regular vision screening during the school years and the need for comprehensive but flexible back-up services.

Adolescent

Vision screening of adolescents and their use of glasses.

Vision screening was performed in over 11 000 16-year-olds who were taking part in the National Child Development Study. For distance vision 75% had normal acuity, 9% a minor defect, and 16% a more severe unilateral or bilateral defect. For near vision 85% had normal vision, 8% a minor defect, and 7% a unilateral or bilateral defect. Few children (62) with normal distant vision had defects in near vision, though many more (607) had both poor distant vision and poor near vision. Vision defects were more common in girls than in boys and occurred more often in adolescents from non-manual than manual families. Athough 18% of children had been prescribed glasses for current use, a third did not have their glasses available at the examination: 27% of the children prescribed glasses had normal unaided distant visual acuity or only a minor defect, and they constituted 42% of those who were not wearing their glasses. Further investigation is needed into the criteria on which glasses are prescribed for children and into the reasons for which they are not worn.

Adolescent

Vision screening in a primary care setting. A missed opportunity?

To determine the effectiveness of vision screening in a primary care setting, we administered a questionnaire and a vision test to 458 patients from a general medical clinic. Subjects were referred for complete ophthalmologic evaluation if they failed the vision test or met other "high-risk" criteria based on information contained in the questionnaire. Patient-initiated requests for eye examinations were also honored. A total of 169 patients were scheduled for eye examinations, and 148 actually underwent ophthalmologic evaluation. One hundred one of those examined were referred on the basis of the study criteria. "Serious eye disease" (cataract, glaucoma, diabetic retinopathy, or age-related macular degeneration) was diagnosed in 96 (95%) of these patients. Prompt surgical intervention was recommended in 27 (27%), and medical treatment was begun in 21 (21%). Of those with serious eye disease, 59% met the criteria by failing the vision test, while 69% met the high-risk criteria determined by the questionnaire. Of the 148 subjects who received ophthalmologic evaluations, 47 requested them. Serious eye disease was diagnosed in 23 (50%) of the 47 patients. None of these individuals required immediate surgery, and medical treatment for glaucoma was begun in eight (17%). These data suggest that screening for serious eye disease in a primary care setting is an efficient mechanism to use for the identification of patients with undetected ocular disorders that require follow-up or treatment.

Aged

Comparison of the automated vision screening test to the Snellen test.

The comparison of an automatic vision screening machine using the Landolt rings and the usual Snellen Chart was carried out among 123 second grade and 149 fifth grade students in an elementary school in Jerusalem. The sensitivity of the test for a cut-off point of greater than or equal to 6/12 according to the Snellen test was 41.7% (CI = 16.5-71.4) and the specificity was 86.5% (CI 78.1-92.2) for second graders. For fifth graders the values were 50.0% (CI = 20.1-79.9) and 90.6% (CI 83.7-94.8) respectively. Diagnosis by a specialist decreased the number of 'false negatives' and confirmed the pathological cases. The automatic test was well accepted by the children. Though more time is needed for assessment using the automatic test, its advantage is that no professional staff are required.

Child

Comparison of vision screening by lay and professional personnel.

A previously described vision screening procedure was administered to 652 elementary school children, using lay volunteers. These students were later screened by optometrists, using the Modified Clinical Technique (MCT). Using MCT as the standard, the lay screening correctly identified 90% of the children; the incorrect identifications included 28 children (4.3%) as false negatives and 36 children (5.5%) as false positives. Analysis indicates a lower cost for the combined lay and professional screening than for professional screening alone.

Allied Health Personnel

An audit of preschool vision screening.

An audit was carried out to clarify the dispute surrounding the vision screening test at 3.5 years. The uptake was 53.5%, sensitivity 77%, specificity 96%, and positive predictive value 50%. In particular the uptake was poor and the test needed a clear policy for the future.

Child, Preschool

Stereopsis testing to reduce overreferral in preschool vision screening.

Three- and 4-year-old children who obtain the minimum failing visual acuity result of one-line difference between eyes in preschool vision screening with isolated optotypes have a high rate of overreferral. We evaluated the Random Dot E Stereotest (RDES) to determine if a passing result at a high threshold on this test, as administered by lay screeners, could safely nullify referral for a minimum failing visual acuity test result. Fifty-eight children with a "one-line difference" result also had the RDES administered to them during screening at distances of 40 cm and 1.5 m. Upon subsequent ophthalmologic examination, 45 of these children were found to be normal, and 13 had abnormal findings. Thirty-nine of the children with normal examinations had correctly passed the RDES at 1.5 m. Seven of the 13 children with abnormal findings had correctly failed the RDES. Thus, the specificity of stereotesting was 87% and the sensitivity was 54%. Among the six children who falsely passed the stereopsis test during screening, best-corrected visual acuity was no worse than 20/40 and no child had greater than a one-line difference in acuity. Therefore, no amblyopia was missed. If a passing result on the stereotest at 1.5 m had been allowed to nullify a one-line difference referral, overreferral would have decreased 87% but underreferral would have increased 46%. We cannot yet recommend modifying current visual acuity referral criteria based on stereopsis testing results until the sensitivity of stereopsis screening by lay screeners at a sufficient threshold is improved.

Child, Preschool

The Tokyo Metropolitan Home Vision Screening Program for amblyopia in 3-year-old children.

In August 1989, the Tokyo Metropolitan Government officially began a vision screening program for children aged 3 years 1 month. A 1988 pilot study of 1,303 children this age disclosed five cases (0.38%) of amblyopia. The home vision test, which uses picture cards of familiar figures, proved to be an efficient and inexpensive method of screening when incorporated into the existing health-check program for 3-year-old children. In the initial eight months of the program, 21,906 children were screened. Of these, 419 children (1.9%) were referred to an ophthalmologist for follow-up, and amblyopia was detected in 41 children (0.19%).

Amblyopia