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Alaska Blind Child Discovery

A cooperative, charitable research project to vision screen every preschool Alaskan

School Nursing HOTV vs Photoscreen

Early detection of significant vision problems in children is a high priority for pediatricians and school nurses. Routine vision screening is a necessary part of that detection and has traditionally involved acuity charts. However, photoscreening in which "red eye" is elicited to show whether each eye is focusing may outperform routine acuity testing in pediatric offices and schools. This study compares portable acuity testing with photoscreening of preschoolers, kindergarteners, and 1st-graders in 21 elementary schools. School nurses performed enhanced patched acuity testing and two types of photoscreening in a portable tent. Nearly 1,700 children were screened during spring semester 2004, and 14% had confirmatory exams by community eye care professionals. The results indicate that one form of photoscreening using a Gateway DV-S20 digital camera is significantly more sensitive to children with significant vision problems, as well as being the most cost effective (85% specificity and only $0.11 per child). This suggests that the adaptation of photoscreening into a routine vision screening protocol would be beneficial for efficiently detecting vision problems that could lead to amblyopia
Photoscreening may outperform routine acuity testing in pediatric offices, however both have fairly good validity when performed by specialists in preschool vision screening.
School nurses performed patched HOTV surround acuity testing and two types of photoscreening (MTI and Gateway DV-S20) on 1700 children (696 1st grade, 710 Kindergarteners, and 271 special-needs pre-Kindergarten). 14% had comprehensive exams and another 65% had normal photoscreens combined with patched acuities of 20/25 or better OU. Nurses were queried as to their preferences of these new modalities and the relative costs were estimated.
Photoscreening time/cost took about 40 seconds and $0.10 (Gateway) to $2.00 (MTI) per student and patched acuity about 150 seconds/8 cents per student. We estimate the overall sensitivity/specificity using AAPOS guidelines for the modalities to be 39%:99% for patched HOTV acuity, 77%:99% for MTI photoscreening, and 85%:98% for Gateway photoscreening. The specificity of acuity testing was particularly low in pre-K due to 33% unable to complete the test. Nurses markedly preferred patched HOTV acuity cards over their former Snellen wall charts and favored photoscreening more in younger students.
Nurses preferred inexpensive, mobile HOTV acuity cards with patching of the non-tested eye. Photoscreening in younger elementary school children was more sensitive than patched acuity and would be cost-effective for most school districts.
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Leman RE, Clausen MM, Bates J, Stark L, Arnold KK, Arnold RW. A comparison of patched HOTV visual acuity and photoscreening. J School Nursing. August 2006;22(4):237-243.  


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