The lifetime impact of amblyopia on an individual justifies large-scale societal screening programs in most developed countries. But which implementation yields the best results for the effort? Some believe that if they can detect refractive amblyopia risk factors earlier in children, treatment can start quickly and may be easier, and perhaps a portion of amblyopia or strabismus cases can be prevented altogether. However, a recent meta-analysis has suggested there is weak evidence of optimum timing, frequency or referral criteria regarding photoscreening to maximize outcomes whilst minimizing monetary and societal costs. Therefore, the researchers have noted that the most cost-effective option for parents seems to be a later, expert VA screening with the opportunity for a re-test before referral.

This review assessed all English language photoscreening literature through September 2018. Of 370 abstracts reviewed, 55 reported large-scale community photoscreening projects. The researchers noted photoscreening was a stand-alone, single test event in 71% of projects.

EUSCREEN project country reports that described how photo- and automated screening is used internationally revealed that, if adopted, photoscreening often supplements other tests in established programs and is rarely used as a stand-alone test. The researchers found that photoscreening is being widely adopted, and in many different ways, but with poor availability of local, regional or national protocols, audit or monitoring of long-term outcomes or costs.

Reported costs varied widely and evidence of cost-effectiveness was sparse in the literature, or in international practice. Only 13% of papers compared the diagnostic accuracy or cost-effectiveness of photoscreening and VA testing, and when they did, cost-effectiveness of photoscreening compared unfavorably.          

“There is no doubt that amblyopia should be detected before seven years of age, beyond which it becomes much harder to treat, but from a public health viewpoint, the optimum timing and nature of that screening is still not established,” the researchers proposed. “There is a need for clear evidence that the extra post-screening costs incurred by photoscreening for risk factors, especially if carried out on infants and very young children, are justified by improved overall outcomes.”

Horwood AM, Griffiths HJ, Carlton J, et al. Scope and costs of autorefraction and photoscreening for childhood amblyopia—a systematic narrative review in relation to the EUSCREEN project data. Eye (Lond). November 30, 2020. [Epub ahead of print].