The Use of a Mobile Van for School Vision Screening: Results of 63 841 Evaluations


To present data from an established mobile screening program for children in the amblyogenic age group using gold-standard examination techniques by eye care professionals.


Retrospective 12-year, cross-sectional study.


setting : Single center. study population : All children enrolled in pre-kindergarten, kindergarten, and first grades in public schools in Cleveland, Ohio were eligible for evaluations. intervention procedure : An ophthalmic technician and/or optometrist examined children in a customized van that visits all elementary schools. The initial screening included testing of monocular near and distance visual acuity, stereoacuity, ocular alignment, motility, pupils, and external abnormalities. Children meeting the 2003 American Academy of Pediatrics vision screening referral criteria underwent cycloplegic retinoscopy and ophthalmoscopy by the on-site optometrist and received glasses. In addition, these children were referred to pediatric ophthalmology for ongoing care. main outcome measure : Determination of the proportion of children with refractive errors, amblyopia, and/or strabismus.


Between 2002 and 2014, 63 841 evaluations were performed, representing approximately 55% of eligible children. Overall, 6386 (10.0%) of children met 1 or more referral criteria: 5355 (8.39%) received glasses, 873 (1.37%) had amblyopia, and 1125 (1.76%) had strabismus. Over the 12-year period, there was no statistically significant change in the prevalence of strabismus (1.73%–2.24%, P = .91) or amblyopia (0.9%–2.08%, P = .13) among first grade students.


Amblyopia, strabismus, and refractive errors are common in young children. During the study period, the rates of amblyopia and strabismus remained stable, indicating the need for continued vision screening and treatment services. A van-based model, traveling directly to schools, appears to be effective in reaching young children in underserved communities.

Amblyopia and strabismus are significant public health issues that can cause permanent reductions in vision. Amblyopia is the leading cause of monocular vision loss in Americans aged 20–70 and is associated with lower rates of college graduation and worse psychological functioning. Strabismus is similarly associated with adverse effects related to interpersonal relationships, work, and education.

There is widespread support for pediatric vision screening among medical organizations such as the American Academy of Ophthalmology (AAO), American Academy of Pediatric Ophthalmology and Strabismus (AAPOS), and American Academy of Pediatrics (AAP). Despite this support, many children are not screened. Research on the effectiveness of screening programs is somewhat limited and it would be unethical to conduct a randomized controlled trial to assess the benefits of pediatric vision screening because the benefits for treating amblyopia are well recognized.

AAPOS recommends various techniques for pediatric vision screening, including age-appropriate visual acuity testing, photoscreening, and autorefraction. Vision screenings for amblyopia and amblyopia risk factors take place in community centers, pediatrician offices, and schools. Studies have shown poor rates of screening by medical providers and poor referral rates when screenings lead to abnormal or indeterminate results. The Lions Club has championed the use of trained volunteers to screen preschool children in community settings. These programs tend to have low sensitivity rates, with the Iowa photoscreening program reporting a sensitivity of 52%. Although many state programs have follow-up rates with eye care professionals of less than 50% for children who fail the screening, the Iowa program demonstrated commendable follow-up rates (76.5%–89.5%) after establishing a full-time follow-up coordinator.

The Vision First program was designed in partnership with the Cleveland Metropolitan School District, also referred to as the Cleveland Public Schools in this manuscript, as an effort to provide free vision screening and treatment for children enrolled in public schools within the city of Cleveland, Ohio. Vision First was designed to address the challenges of many screening programs, including poor referral rates that lead to incomplete evaluations and diagnosis of vision problems, limitations of current screening technologies, and low follow-up rates with eye care professionals. Data from the first 4 years of Vision First were previously published. Here we present 12 years of data from Vision First, an integrated model for screening, eye care professional evaluation, and treatment of eye diseases in children attending pre-kindergarten, kindergarten, and first grade in Cleveland, Ohio.


Screening results from the first 12 years of the Vision First program were reviewed as a retrospective 12-year, cross-sectional study. All data was de-identified in order to ensure patient confidentiality. The Cleveland Clinic Foundation Institutional Review Board (IRB) approved this retrospective study. The research was conducted in accordance with the Declaration of Helsinki and both state and federal laws.

Screening Process

Vision First aims to evaluate and treat each child enrolled in pre-kindergarten, kindergarten, or first grade at any public school in the city of Cleveland. Children with disabilities enrolled in the Division of Special Education are not included in the program because all of these children are required to have annual, full eye examinations. The Vision First program coordinator works with the nurse or principal at each school to establish a predetermined schedule prior to the start of the academic year. The program coordinator determines the number of times the van will visit each school based on school enrollments. The program requires parental consent forms for screenings and the administration of eye drops. School nurses and classroom teachers ensure the forms are provided to each student’s caregivers.

All evaluations take place inside the Vision First mobile van, which is a customized recreational vehicle with 2 screening lanes. Vision First personnel travel to each school and set up the van in the school parking lot or near the school entrance. Evaluations are conducted by an optometrist and an ophthalmic technician (who serves as the program coordinator and van driver).

Every child undergoes an initial screening that includes an assessment of monocular near and distance visual acuity using a Snellen chart or Allen figures, stereoacuity using the Titmus test, ocular alignment using cover and alternate cover tests, testing of extraocular movements, pupils, color vision (male subjects only), and pen light inspection for external abnormalities.

Children meeting the 2003 American Academy of Pediatrics vision screening referral criteria ( Table 1 ) immediately undergo a detailed examination by the on-site optometrist. These children receive cyclopentolate 1% and/or tropicamide 1% drops, depending on their iris color. Thirty minutes later, these children undergo cycloplegic retinoscopy and indirect ophthalmoscopy of the optic nerve and posterior pole by the on-site optometrist. Visual acuity is repeated using the cycloplegic refraction for all children with visual acuity ≤20/40 (kindergarten and first grade) or <20/40 (pre-kindergarten). Results are documented in a paper chart and basic biographical information and recommendations are summarized in a database (name, date, date of birth, visual acuity, screening pass vs failure, and failure reason, if applicable). A letter is mailed to each child’s home address with the results of the child’s evaluation (pass, failure, or unable to complete).

Table 1

Failure and Referral Criteria Used for Initial Vision Screenings in Students Enrolled in Pre-kindergarten, Kindergarten, and First Grade


  • Visual acuity worse than 20/40 in either eye for pre-kindergarten students

  • Visual acuity 20/40 or worse in either eye for kindergarten and first grade students

  • Two-line difference in visual acuity between each eye

  • Stereoacuity less than 3/3 animals (100 seconds of arc) for pre-kindergarten students (stereoacuity is tested with the Titmus test; Stereo Optical, Chicago, Illinois, USA)

  • Stereoacuity less than 5/9 circles (100 seconds of arc) for kindergarten and first grade students (stereoacuity is tested with the Titmus test; Stereo Optical, Chicago, Illinois, USA)

Alignment and motility:

  • Any manifest ocular deviation, regardless of magnitude

  • Any vertical phoria

  • Esophoria greater than 8 prism diopters or exophoria greater than 15 prism diopters

  • Any muscle overaction or any restricted eye movement


  • Relative afferent pupillary defect, anisocoria, or iris heterochromia

  • Any nystagmus

  • Any external abnormality (ptosis, abnormal globe size, or anomalous head position)

All children enrolled in pre-kindergarten, kindergarten, or first grade at any public school in Cleveland, Ohio are eligible for a free vision evaluation if parents sign a permission form. The initial screening includes testing of monocular distance and near visual acuity, stereoacuity, ocular alignment, motility, and pupils.

Children meeting any of the above criteria undergo a detailed examination with a cycloplegic refraction and a dilated fundus examination by an on-site pediatric optometrist. In addition, children meeting any of these criteria are referred to pediatric ophthalmology for ongoing care.

All children with a refractive error that meets prescription guidelines ( Table 2 ) are provided a free pair of spectacles. For the first 5 years, children were simply given a prescription and a voucher for a free pair of spectacles. Since academic year 2007–2008, children select a spectacle frame from up to 60 options prior to leaving the van. The program coordinator orders the glasses and a local optician visits each school to adjust the glasses to fit each child. The glasses are then given to the parents.

Table 2

Spectacle Prescription Criteria for Children With Refractive Errors

Subjects Prescription Criteria
Children with strabismus
Any esodeviation Full cycloplegic hyperopic refraction
Exophoria (>10 PD) Full myopic refraction
Lowest hyperopic refraction that maintains best-corrected VA
Children with a failing VA
Myopia Full cycloplegic refraction
Hyperopia Cycloplegic refraction reduced by +1.50
Astigmatism Full cycloplegic refraction if astigmatism is greater than 0.50
Children with passing VA a
Myopia Full cycloplegic refraction if a child squints
Hyperopia Full cycloplegic refraction if any esodeviation is present
Astigmatism Full cycloplegic refraction if a child squints

PD = prism diopter; VA = visual acuity.

All children meeting the initial screening failure and referral criteria ( Table 1 ) underwent a dilated fundus examination and cycloplegic refraction. Children meeting the above spectacle prescription criteria were given a voucher for free spectacles (2002 – spring 2007) or were delivered a free pair of spectacles (fall 2007 – present).

a Children with a passing VA are refracted if they meet any failure criteria listed in Table 1 .

Children were diagnosed with amblyopia if either the visual acuity, with cycloplegic correction, was <20/40 in pre-kindergarten children or ≤20/40 in older children or there was a 2-line difference between each eye. Children were diagnosed with strabismus if there was any manifest vertical or horizontal deviation. Children were not classified as having strabismus if they had a phoria.

Referral Process

All children who meet the 2003 American Academy of Pediatrics vision screening referral criteria ( Table 1 ) are referred to a pediatric ophthalmologist for follow-up care. A list of all pediatric ophthalmologists, including private practice, academic, and county hospital–affiliated ophthalmologists, in the Cleveland metropolitan area is included in the referral letter. In addition, school nurses are provided with a list of all children at their school who are referred to pediatric ophthalmology. The program coordinator calls the parents of each child who is referred to pediatric ophthalmology to determine if the child had follow-up care and to answer any questions. The program coordinator works with the school nurse to ensure that all children who fail the initial screening are seen the following academic year if they are still enrolled in pre-kindergarten, kindergarten, or first grade.

Statistical Analysis

Statistical analyses were conducted using SAS Version 9.3 (SAS Institute Inc, Cary, North Carolina, USA). Trend analysis was conducted using the Cochran-Armitage Trend Test with a P value less than .05 considered statistically significant.

Rates of amblyopia and strabismus among first grade students were analyzed to determine if there was a decrease in prevalence rates over time. Pre-kindergarten and kindergarten students were eligible for repeat examinations, so comparing the overall prevalence rates of amblyopia or strabismus by year would result in the comparison of nonunique populations. Instead, we selected the cohort of first grade students in order to have unique groups for the statistical analysis. The first grade was chosen because first graders make up 44% of all students examined and because these students had the opportunity to undergo screenings during the 2 prior years.

The proportion of students screened was calculated by dividing the number of students screened by the total Cleveland Public Schools enrollment for grades pre-kindergarten, kindergarten, and first grade. This calculation is an estimate because enrollment data include the approximately 150 students in the Division of Special Education although these students are excluded from Vision First. Enrollment data were available for the last 6 academic years from 2008–2009 to 2013–2014.


Between 2002 and 2014, 63 841 evaluations were performed ( Table 3 ). Of those evaluated, 49.4% were male. The mean age for children evaluated was 6.27 years (range: 3.0–10.9 years, standard deviation 0.85). Children were evaluated at every public school every year (71–88 schools). Overall, 6386 (10.0%) met 1 or more referral criteria with 5355 (8.39%) given a voucher for a free pair of glasses or dispensed a free pair of glasses, 873 (1.37%) having amblyopia, and 1125 (1.76%) having strabismus. During the first 5 years, 2274 students were given a voucher, and since 2007–2008 3081 students received a free pair of glasses delivered to their school and adjusted by an optician. The vast majority of children were able to cooperate with visual acuity testing. Most of the children who were unable to cooperate underwent a detailed examination with the optometrist. Referral letters were sent to parents of all children who were unable to complete any part of the evaluation.

Table 3

Vision First Screening Results for Children in Pre-kindergarten, Kindergarten, and First Grade

Academic Year Children Evaluated a Failed Initial Screening b Glasses Dispensed c Amblyopia d Strabismus e
2002–2003 5085 490 (9.6%) 397 (7.8%) 72 (1.4%) 131 (2.6%)
2003–2004 6387 476 (7.5%) 373 (5.8%) 118 (1.8%) 127 (2.0%)
2004–2005 6218 660 (10.6%) 558 (9.0%) 116 (1.9%) 103 (1.7%)
2005–2006 5298 537 (10.1%) 449 (8.5%) 91 (1.7%) 118 (2.2%)
2006–2007 5650 577 (10.2%) 497 (8.8%) 85 (1.5%) 101 (1.8%)
2007–2008 5481 660 (12.0%) 578 (10.5%) 86 (1.6%) 90 (1.6%)
2008–2009 5663 567 (10.0%) 430 (7.6%) 55 (1.0%) 99 (1.7%)
2009–2010 5505 566 (10.3%) 490 (8.9%) 44 (0.8%) 83 (1.5%)
2010–2011 5184 508 (9.8%) 430 (8.3%) 60 (1.2%) 82 (1.6%)
2011–2012 4741 492 (10.4%) 417 (8.8%) 45 (0.9%) 70 (1.5%)
2012–2013 4367 427 (9.8%) 365 (8.4%) 58 (1.3%) 65 (1.5%)
2013–2014 4262 426 (10.0%) 371 (8.7%) 43 (1.0%) 56 (1.3%)
Total 63 841 6386 (10.0%) 5355 (8.4%) 873 (1.4%) 1125 (1.8%)

Only gold members can continue reading. Log In or Register to continue

Stay updated, free articles. Join our Telegram channel

Jan 6, 2017 | Posted by in OPHTHALMOLOGY | Comments Off on The Use of a Mobile Van for School Vision Screening: Results of 63 841 Evaluations

Full access? Get Clinical Tree

Get Clinical Tree app for offline access