SPOT Vision Screening and Corrective Lenses
Yes, corrective lenses (both glasses and contact lenses) should be removed before performing SPOT photoscreening to obtain accurate baseline refractive measurements.
Rationale for Lens Removal
SPOT photoscreening is designed to detect underlying refractive errors, strabismus, and amblyopia risk factors by measuring how the eyes focus light. The device needs to assess the eye's natural refractive state without optical correction to:
- Identify the actual refractive error that requires correction
- Detect amblyopia risk factors based on uncorrected refractive values
- Determine appropriate referral criteria (typically values <-3D or >+2.5D for sphere, >1.5D for astigmatism, >1D for anisometropia) 1
How Photoscreening Works
Photoscreening is a photographic method that determines whether a child's eyes focus properly by detecting hypoaccommodation and establishing the minimal optical correction needed 2. The technology evaluates the eye's focusing ability from approximately 6 months of age onward 2, 3.
When corrective lenses are worn during screening, they mask the underlying refractive error, making it impossible to:
- Accurately measure the true refractive state
- Properly assess whether the current correction is adequate
- Identify progression of refractive errors
Clinical Application
For Glasses Wearers:
- Remove spectacles completely before screening
- Ensure the child can maintain fixation without correction
- Document that screening was performed without correction
For Contact Lens Wearers:
- Remove contact lenses before the screening procedure
- This aligns with standard practice of removing contact lenses for comprehensive eye examinations 4
- Patients should have backup spectacles available for vision after lens removal 4
Important Caveat
The only scenario where you might screen with correction is when specifically evaluating the adequacy of current optical correction or monitoring treatment effectiveness 3. However, this would be a secondary screening after obtaining baseline uncorrected measurements, and should be clearly documented as "screening with correction" to avoid misinterpretation of results.