Clinical Brief – September 11th
The USPSTF now recommends screening kids between 3 to 5 years old at least once for lazy eye or its risk factors (USPSTF = US Preventive Services Task Force).
What’s lazy eye?
Lazy eye is a childhood condition where vision in one eye doesn’t develop properly.
In children under 6, lazy eye and its risk factors may be about as common as nearsightedness in the US. According to the USPSTF, 1-6% of these kids have lazy eye or its risk factors vs 4% with nearsightedness.
They estimate that the lifetime risk of vision loss in people with lazy eye is at least 1.2%.
Why screen for lazy eye?
Finding lazy eye and treating it early is likely to result in “permanent improvements in vision throughout life,” says the USPSTF.
Treatments for lazy eye that were evaluated include eye patching and/or eyeglasses. They didn’t find any eligible studies looking at atropine eye drops or vision therapy. They also didn’t look at surgical options.
Generally, studies evaluating eye patching and/or eyeglasses saw improvements from baseline in visual acuity. Benefits were greater for kids with more visual impairment before treatment.
What are the risks of screening and treatment?
Whenever we think about screening, we worry about over-diagnosis and exposing people to unnecessary side effects associated with treatment, as well as psychological distress.
Here, the USPSTF found that in general, false-positives were usually >75% in studies where the prevalence of vision problems is low (<10%). In studies wither higher prevalence rates, the false-positives were less common, usually <35%.
As for treatment, eye patching and eyeglasses are arguably minimally invasive treatments.
Studies reviewed by the USPSTF showed no adverse events were linked to these treatments. They also didn’t seem to affect a kid’s “happiness” or cause “behavioral problems”.
More children were “upset” about the treatment though, with patching than with eyeglasses alone. This seemed to drop as they got older.
The USPSTF recommendation seems to me fairly reasonable. There are potentially significant gains for correcting lazy eye early with eye patching and/or eyeglasses. The downsides of over-diagnosis shouldn’t be ignored, but it’s good to see that no physical harm was reported with these treatments.
In terms of feasibility, they say that about 40% of kids in the US who are 3 years old are already getting routine vision screening, which includes some risk factors of lazy eye. Screening kids who are younger than 3 might be tough though, given their age.
“The USPSTF recommends vision screening at least once in all children aged 3 to 5 years to detect [lazy eye] or its risk factors.
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of vision screening in children younger than 3 years.”