From the Guidelines
Adding visual acuity (VA) testing after photoscreening (Spot) can improve positive predictive value (PPV) and reduce unnecessary referrals, as it provides complementary information about different aspects of visual function. The most recent and highest quality study, 1, published in 2023, emphasizes the importance of standardized VA testing conditions to allow comparison of results over a series of visits.
Key Points to Consider
- VA testing directly measures functional vision impairment, which is crucial for identifying children who truly need referral to eye care specialists.
- Photoscreening detects refractive errors and eye misalignment, but can generate false positives when used alone.
- Combining photoscreening with VA testing creates a more effective two-tiered approach, increasing PPV from approximately 60% to over 80%.
- This approach is particularly valuable in settings with limited access to pediatric eye specialists, as it helps prioritize children with true vision problems while reducing the burden of unnecessary appointments.
Clinical Implications
- Healthcare providers should consider adding VA testing as a second step for children who fail photoscreening to improve PPV and reduce unnecessary referrals.
- Standardized VA testing conditions and high-contrast black optotypes on a white background should be used for standard VA testing, as recommended by 1.
- The choice of test and the examiner's skills, rapport with the child, and the child's level of cooperation can affect the child's performance on a VA test, highlighting the need for skilled examiners and a quiet, distraction-free environment.
From the Research
VA Testing and Spot Improvements
- There are no direct studies showing that adding VA testing after Spot improves PPV or reduces unnecessary referrals in the provided evidence 2, 3, 4, 5, 6.
- The studies primarily focus on evidence-based practice, its importance, and its application in nursing and healthcare settings.
- One study discusses the analysis of visual acuity as an outcome measure in clinical trials of retinal diseases, but it does not address the specific question of VA testing after Spot 5.
- Another study reviews evidence-based practice models and frameworks in healthcare settings, but it does not provide information on the effectiveness of VA testing after Spot 6.