Trained Screeners Can Identify Preschoolers
With Vision Disorders
Specially trained nurses and lay people performed
effectively when using certain vision screening tests
to identify preschoolers with vision disorders, according
to a National Institutes of Health-funded research study
of more than 1,400 children.
In comparisons using selected vision screening tests,
trained nurses and lay people were able to correctly
identify up to 68 percent of children with at least
one of the most prevalent vision disorders of childhood:
amblyopia (lazy eye), strabismus (eye misalignment),
refractive errors (poor vision that can be corrected
with glasses or contact lenses) or poor vision not associated
with any obvious disorder. These results demonstrate
that trained lay people and nurses can achieve similar
results when using specific tests to screen preschool
children for vision disorders.
The purpose of the Vision In Preschoolers Study (VIP
Study) is to identify whether vision-screening tests
can accurately identify preschool-aged children who
would benefit from a comprehensive vision examination.
Study personnel evaluated selected children enrolled
in Head Start centers in Berkeley, CA; Boston, MA; Columbus,
OH; Philadelphia, PA; and Tahlequah, OK. The VIP Study
was funded by the National Eye Institute (NEI), part
of the National Institutes of Health. Results from the
second phase of this study are published in the August
2005 issue of the journal Investigative Ophthalmology
and Visual Science. An earlier phase of the VIP Study
found that four commonly used vision screening tests
were more effective than seven other commercially available
tests in recognizing vision problems in preschool-aged
children.
During the first phase of the study, published in the
April 2004 issue of the journal Ophthalmology, licensed
optometrists and ophthalmologists compared 11 commercially
available screening tests for diagnosing eye disorders
in children. They tested 2,588 children in a mobile
van specially designed with four vision screening rooms.
They also gave each child a full eye examination using
established diagnostic examination procedures and tests.
The 11 tests varied widely in performance when they
were administered by the eye care professionals. The
best tests detected two-thirds of children having at
least one of the targeted vision disorders and nearly
90 percent of children with the most important conditions.
Three tests that assessed refractive error (e.g., nearsightedness,
farsightedness, or astigmatism) and one test that evaluated
visual acuity were more accurate than others in detecting
children with vision problems. These tests included
two hand-held autorefractors used to measure refractive
error; retinoscopy, which uses light reflected off the
back of the eye and hand-held lenses to measure refractive
error; and a visual acuity test in which children stand
10 feet away from a chart displaying symbols and name
each symbol as the screener points to it.
“We are excited to have identified the best-performing
tools for vision screening of preschool children, and
to have found that trained lay screeners and nurses
can use those tools effectively,” said Paul A. Sieving,
M.D., Ph.D., director of the NEI. “As early detection
of childhood eye disease increases the likelihood of
successful treatment, these results have important implications
for the visual health of children.”
For the second phase of the study, nurses and lay screeners
administered four vision screening tests to 1,452 children
at their Head Start centers. They screened all children
who had failed a basic Head Start vision screening and
a random sample of those children who passed the screening.
The screening tests included three of the tests that
performed best in the first phase of the study: two
hand-held automated refractors to measure refractive
error (e.g., nearsightedness, farsightedness, or astigmatism);
and a test of visual acuity in which children name or
match symbols at a set distance. The screeners also
administered a test for depth perception in which the
children point to a three-dimensional image. All children
screened also received a standardized, comprehensive
eye examination by a licensed eye care professional
in a specially equipped vision van at the child’s Head
Start Center.
The results demonstrated that trained nurses and lay
screeners achieved similar accuracy rates administering
the two automated refractors. Nurses correctly identified
up to 68 percent of children with vision disorders while
lay screeners correctly identified up to 62 percent
of these children. Using these hand-held instruments,
nurses and lay screeners correctly identified more than
80 percent of children with conditions considered most
severe.
Using charts displaying several symbols at one time
at a distance of 10 feet, nurses and lay screeners were
not able to correctly identify as many children with
vision disorders. However, when lay screeners administered
a simpler version of the symbols visual acuity test
at a distance of five feet, they correctly identified
61 percent of children with vision problems. Nurses
and lay screeners identified about the same percentage
of children with vision problems (45 percent versus
40 percent) using the test of depth perception.
The researchers estimate that, nationwide, two to five
percent of children ages three to five have amblyopia,
three to four percent have strabismus, and 10-15 percent
have significant refractive error.
“It is estimated that up to 15 percent of preschool
children between the ages of three and five have an
eye or vision condition that, if not corrected, can
result in reduced vision,” said Paulette P. Schmidt,
O.D., M.S., chairperson of the VIP Study and a professor
of optometry and vision science at The Ohio State University
College of Optometry. “Unfortunately, many parents are
unaware that their child has an eye problem because
vision problems do not hurt and children do not know
how well they should see.”
“Accurate and efficient identification of preschool
children with vision disorders has a significant impact
on visual outcome,” Schmidt said. "Parents should question
which eye problems are being screened for, the accuracy
of the tests, and how often serious eye conditions are
missed by these tests," she said. "If results from a
vision screening test indicate that a child should have
a follow-up examination, parents should ask about next
steps. Parents also should be aware that vision screening
programs do not substitute for a comprehensive eye examination
by a licensed eye care professional. However, vision
screening may be a valuable way to detect children who
would benefit most from an eye examination."
Planning is now underway for a third phase of the VIP
Study. A list of study centers is attached.
Vision In Preschoolers (VIP) Study Centers
Berkeley, CA. University of California Berkeley School
of Optometry
PI: Deborah Orel-Bixler, PhD, OD.
School of Optometry
University of California, Berkeley
200 Minor Hall
Berkeley, CA 94720-2020
Phone: 510-642-2402
Fax: 510-643-5109
Email: dob@uclink.berkeley.edu
Boston, MA. New England College of Optometry
PI: Bruce Moore, OD.
New England College of Optometry
1255 Boylston Street
Boston, MA 02215
Phone: 617-236-6309
Fax: 617-369-0198
Email: mooreb@ne-optometry.edu
Columbus, OH. The Ohio State University College of
Optometry
Study Chair and PI: Paulette Schmidt OD, MS
VIP Study Center Office
The Ohio State University
College of Optometry
P.O. Box 182342
Columbus, OH 43218-2342
Phone: 614-292-3189
Fax: 614-247-6907
Email: schmidt.13@osu.edu
Marjean Taylor Kulp, OD, MS
(Co-Investigator).
College of Optometry
The Ohio State University
P.O. Box 182342
Columbus, OH 43218-2342
Phone: 614-688-3336
Fax: 614-247-6907
Email: MTKulp@optometry.osu.edu
Philadelphia, PA. Pennsylvania College of Optometry
PI: Elise Ciner, OD.
Pennsylvania College of Optometry
1200 West Godfrey
Philadelphia, PA 19141
Phone: 215-276-6059
Fax: 215-276-6196
Email: Eciner@pco.edu
Tahlequah, OK. Northeastern State University College
of Optometry
PI: Lynn Cyert, PhD, OD.
College of Optometry
Northeastern State University
1001 North Grand Avenue
Tahlequah, OK 74464
Phone: 918-456-5511; Ext 4007
Fax: 918-458-9603
Email: cyert@nsuok.edu
Coordinating Center: Philadelphia, PA. University
of Pennsylvania, Department of Ophthalmology
PI: Maureen Maguire, PhD.
VIP Coordinating Center
3535 Market Street, Suite 700
Philadelphia, Pa 19104-3309
Phone: 215-615-1501
Fax: 215-615-1531
Email: maguirem@mail.med.upenn.edu
The National Eye Institute is part of the National
Institutes of Health (NIH) and is the Federal government's
lead agency for vision research that leads to sight-saving
treatments and plays a key role in reducing visual impairment
and blindness. The NIH is an agency of the U.S. Department
of Health and Human Services.
The National Institutes of Health (NIH) — The
Nation's Medical Research Agency — is comprised
of 27 Institutes and Centers and is a component of
the U. S. Department of Health and Human Services.
It is the primary Federal agency for conducting and
supporting basic, clinical, and translational medical
research, and investigates the causes, treatments,
and cures for both common and rare diseases. For more
information about NIH and its programs, visit www.nih.gov. |