Comparing LEA numbers low vision book and Feinbloom visual acuity charts

Area of Science:

• Ophthalmology
• Low Vision Research

Background:

• Accurate visual acuity measurement is crucial for diagnosing and managing visual impairment.
• Standard charts like the Early Treatment of Diabetic Retinopathy Study (ETDRS) chart are effective but may not always be practical.
• Handheld charts offer potential alternatives for clinical settings.

Purpose of the Study:

• To assess the accuracy and repeatability of the LEA numbers low vision book (LNLVB) and Feinbloom chart.
• To compare these charts against the established ETDRS chart for visually impaired subjects.
• To determine their suitability as alternatives in low-vision assessments.

Main Methods:

• Distance visual acuities were measured using LNLVB, Feinbloom, and ETDRS charts.
• Measurements were repeated within 30 minutes to evaluate test-retest repeatability.
• Correlation and limits of agreement were calculated between charts for 18 visually impaired participants (9 children, 9 adults).

Main Results:

• LNLVB showed better agreement with ETDRS (R=0.953) than the Feinbloom chart (R=0.905).
• Test-retest repeatability was high for all charts, with ETDRS (R=0.976) slightly superior to LNLVB (R=0.954) and Feinbloom (R=0.942).
• Both handheld charts measured slightly worse acuity than ETDRS but demonstrated strong correlations.

Conclusions:

• The LNLVB demonstrates a slight advantage over the Feinbloom chart in agreement with the ETDRS chart.
• Both LNLVB and Feinbloom charts exhibit comparable and high repeatability in low-vision settings.
• These handheld charts are viable alternatives to the ETDRS chart when practicality is a concern.