What is known about the sensitivity of Spot (Autorefractor) in detecting hyperopia, amblyopia, or subtle bilateral blur?

From the Guidelines

Spot vision screeners have limited sensitivity in detecting hyperopia, amblyopia, and subtle bilateral blur, and their use should be supplemented with traditional visual acuity testing for comprehensive vision assessment. According to the most recent and highest quality study 1, vision screening should be performed periodically throughout childhood, and the combined sensitivity of a series of screening encounters is much higher than that of a single screening test. The American Academy of Pediatrics (AAP) recommends vision screening at all well-child visits for children starting in the newborn period to 3 years, and the USPSTF recommends vision screening for children 3 to 5 years of age to detect amblyopia or its risk factors 1.

Limitations of Spot Vision Screeners

• Spot may miss significant hyperopia, particularly when it's less than +3.50 diopters, as these children can often compensate by accommodating during screening.
• For amblyopia detection, Spot relies on identifying risk factors like anisometropia (unequal refractive error between eyes) or strabismus rather than directly measuring visual acuity, which can lead to missed cases of amblyopia without these specific risk factors.
• Regarding subtle bilateral blur, Spot may not effectively identify mild to moderate bilateral refractive errors, especially when they affect both eyes equally, as the device primarily flags significant differences between eyes or extreme refractive errors.

Importance of Traditional Visual Acuity Testing

• Traditional visual acuity testing remains important for comprehensive vision assessment, particularly for conditions where a child's functional vision may be impaired despite minimal refractive error.
• The earlier amblyopia is detected and properly treated, the higher the likelihood of visual acuity recovery, and untreated or insufficiently treated amblyopia results in permanent visual loss and may have detrimental consequences in educational achievement, sports participation, psychosocial well-being, and occupational selection 1.

Clinical Considerations

• The most common causes of visual impairment in children are amblyopia and its risk factors, and refractive error not associated with amblyopia, which includes myopia (nearsightedness) and hyperopia (farsightedness) 1.
• Various tests are used widely in the United States to identify visual defects in children, and the choice of tests is influenced by the child’s age.
• Suitable treatment options for amblyopia include optical correction, patching, pharmacological treatment, optical treatment, Bangerter (translucent) filters, and digital therapeutics, in addition to managing the underlying cause of amblyopia 1.

From the Research

Sensitivity of Spot in Detecting Hyperopia, Amblyopia, or Subtle Bilateral Blur

• The sensitivity of Spot in detecting hyperopia, amblyopia, or subtle bilateral blur has been evaluated in several studies 2, 3, 4, 5.
• A study published in 2020 found that the Spot vision screener had low sensitivity for detecting amblyogenic hyperopia, but modifying the hyperopia criteria cutoff to greater than +1.06 D improved the sensitivity from 25 to 80% with 90% specificity 2.
• Another study published in 2019 found that the overall sensitivity of Spot for detecting amblyopia risk factors was 87.7%, with a specificity of 78.0% 3.
• A 2024 study found that the Spot vision screener was most sensitive for amblyogenic risk factors (ARF) myopia, but had relatively poor sensitivity for hyperopia, with sensitivity varying by ocular pigment 4.
• A 2014 study found that the Spot photoscreener had a sensitivity of 80% and specificity of 74% for detecting amblyopia risk factors in children, which increased to 87% sensitivity with the revised 2013 AAPOS referral criteria 5.
• The sensitivity of Spot for detecting subtle bilateral blur is not explicitly stated in the provided studies, but its ability to detect amblyopia risk factors, including hyperopia and myopia, suggests it may be useful in identifying subtle bilateral blur as well 2, 3, 4, 5.

Factors Affecting Sensitivity

• The sensitivity of Spot may be affected by variations in ocular pigments, with darker-pigmented eyes having higher sensitivity for hyperopia detection 4.
• The cutoff criteria used for hyperopia detection can also impact the sensitivity of Spot, with a modified cutoff of greater than +1.06 D improving sensitivity 2.
• The age of the child being screened may also impact the sensitivity of Spot, with preschool-aged children having higher sensitivity for amblyopia risk factor detection 3.

Comparison to Other Studies

• The provided studies suggest that Spot has good sensitivity and specificity for detecting amblyopia risk factors, including hyperopia and myopia, although sensitivity may vary depending on the population being screened and the criteria used 2, 3, 4, 5.
• A comparison of Spot to other vision screening devices, such as Plusoptix, found similar sensitivity and specificity for detecting amblyopia risk factors 3.