From the Guidelines
Instrument-based screenings are preferred over visual acuity (VA) tests in pediatric patients to minimize unnecessary examinations or prescriptions for glasses, as they provide more objective measurements of refractive errors and have lower false-positive rates. The most recent and highest quality study, published in 2023 in the journal Ophthalmology 1, supports the use of instrument-based screenings, such as photoscreening and autorefraction, for detecting amblyopia and its risk factors in preschool-aged children. These devices can objectively measure refractive errors and eye alignment without requiring the child's subjective response, making them particularly valuable for preschool-aged children, those with developmental delays, or children who have difficulty cooperating with traditional vision charts.
Some key points to consider when deciding between instrument-based screenings and VA tests include:
- The American Academy of Pediatrics recommends instrument-based screenings for children younger than 3 years, as they are more effective in detecting amblyopia and its risk factors 1.
- VA screenings rely on a child's ability to identify symbols or letters at a specific distance, which can be challenging for younger children and may lead to inconsistent results 1.
- Instrument-based screenings have lower false-positive rates, meaning fewer children without actual vision problems are referred for comprehensive eye exams 1.
- The earlier amblyopia is detected and properly treated, the higher the likelihood of visual acuity recovery, and untreated or insufficiently treated amblyopia can result in permanent visual loss and have detrimental consequences in educational achievement, sports participation, psychosocial well-being, and occupational selection 1.
Overall, the evidence suggests that instrument-based screenings are a more effective and efficient way to detect vision problems in pediatric patients, and they should be preferred over VA tests to minimize unnecessary examinations or prescriptions for glasses.
From the Research
Comparison of Screening Methods
- Instrument-based screenings and visual acuity (VA) tests are two common methods used to detect vision problems in pediatric patients 2, 3.
- A study comparing the Plusoptix Vision Screener (PVS) with gold-standard orthoptic assessment found that the PVS had moderate sensitivity (44%) but high specificity (100%) in detecting factors associated with amblyopia 2.
- Another study found that instrument-based vision screening increased completed screening among 3- to 5-year-old children and was associated with a 15% reduction in referrals to eye care specialists 3.
Referral Rates and Costs
- Earlier VA screening and photoscreening yield higher numbers of referrals due to lower sensitivity and specificity for disease, and a different case mix, compared to later VA screening 4.
- Treatment by an ophthalmologist of a referral at 2 years of age can be more than 10 times more expensive than an orthoptist service receiving referrals at 5 years 4.
- A study found that population-level outcomes from a single high-quality VA screening at 4-5 years can be very good, and total patient-journey costs incurred by earlier detection and treatment are much higher than if screening is carried out later 4.
Effectiveness of Screening Tests
- The Vision in Preschoolers (VIP) Study found that the best screening tests administered by eye care professionals were non-cycloplegic retinoscopy, Retinomax Autorefractor, SureSight Vision Screener, and linear, crowded Lea Symbols VA at 10 feet 5.
- The study also found that trained nurses and/or lay screeners can improve detection of strabismus by combining Stereo Smile II with SureSight 5.
- Repeated testing to achieve the manufacturer's suggested confidence number is valuable and improves specificity when screening using the Retinomax 5.
Recommendations
- The US Preventive Services Task Force recommends vision screening at least once in all children aged 3 to 5 years to detect amblyopia or its risk factors 6.
- The task force concludes that the current evidence is insufficient to assess the balance of benefits and harms of vision screening in children younger than 3 years 6.