New device detects strabismus and amblyopia in young children

By Will Boggs MD

NEW YORK (Reuters Health) - The Pediatric Vision Scanner (PVS) can detect amblyopia and strabismus in children aged two to six years with high sensitivity, researchers say.

"The failure to detect amblyopia during early childhood, when treatment may be most effective, is a serious public health problem," Reed M. Jost from Retina Foundation of the Southwest in Dallas told Reuters Health by email. "Retinal birefringence scanning with the PVS is a novel approach that provides the direct detection of strabismus and amblyopia, rather than the common approach of indirectly assessing refractive error risk factors."

In an earlier pilot study of children 2 to 18 years old, the PVS showed 97% sensitivity and 98% specificity for strabismus and amblyopia, suggesting that it could reliably identify children who need ophthalmological care without the risk of overreferral.

Jost and colleagues, who reported no ties to PVS's developer, REBIScan, Inc, tested a new, less-bulky model of the device that is suitable for routine pediatric care. They compared the performance characteristics with those of the SureSight Autorefractor, which screens for refractive risk factors, in 300 preschoolers.

Just under two-thirds of this referral population (62.6%) had strabismus, amblyopia, or both, while the rest had neither condition, the researchers report in JAMA Ophthalmology, online May 29.

Sensitivity of the PVS (97%) was significantly greater than that of the SureSight Autorefractor (74%). PVS failed to detect only 1 of 131 children with strabismus and only 5 of 115 children with amblyopia. By comparison, SureSight missed 37 of 121 diagnoses of strabismus and 17 of 104 amblyopia diagnoses.

Specificity was also significantly higher for the PVS (87%) than for the SureSight Autorefractor (62%).

"At this time, the PVS needs further study in primary care settings before recommendation can be made about its regular use in the general population," Jost said. "Currently, we are evaluating the performance of the PVS at well-child visits at a private pediatric practice."

"The PVS is intended as a device to provide screening to preschool children at annual well-child visits to detect presence of targeted conditions (strabismus and/or amblyopia), not refractive risk factors," Jost explained. "If the PVS and its technology exhibit high sensitivity and high sensitivity in the well child screening setting, it would identify children with strabismus and amblyopia for early referral when treatment is most successful."

Noelle Matta, a research coordinator at Orthoptist Family Eye Group in Lancaster, Pennsylvania, said, "These devices are innovative and are improving our ability to detect problems early. Pediatric vision screening saves money over mandated comprehensive eye exams. This technology is quick and easy but consumers should look at all the available options to decide what technology would best fit into their practice or screening program."

"Screening devices can be criticized for not being 100% specific and sensitive (which we realize is not realistic); however, I would also like to stress that mandated comprehensive eye exams are also not 100% sensitive and specific," Matta told Reuters Health by email.

"It worries me that some states are moving towards this model; this forces parents to be seen by anyone (an optometrist who is not a physician and often not an expert in children and whose main objective is to sell a parent a pair of glasses even if it is virtually clear glass or a general ophthalmologist who is not equipped at seeing children)," she said. "A 'passed' exam or being given glasses with virtually nothing in them can give a parent a false sense of security when there really might be a problem and the costs of these exams can add billions to our overall health care costs unnecessarily."

"Children at risk for eye disease need to be seen by a specialist, by a pediatric ophthalmologist," Matta added. "Children who pass screenings, have screenings on a regular basis, have no complaints, and have no abnormalities noted by the pediatrician, parents, and teachers should not be subjected to lengthy, unpleasant, and costly exams."

SOURCE: http://bit.ly/1kw5Zcj

JAMA Ophthalmol 2014.

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