Validating Rules for Defining No Improvement of Visual Acuity in Childhood Amblyopia

Area of Science:

• Ophthalmology
• Pediatric Medicine
• Clinical Research

Background:

• Amblyopia treatment requires accurate determination of visual acuity (VA) stability.
• Treatment decisions, such as continuing or altering interventions like patching or spectacles, depend on whether VA has plateaued.

Purpose of the Study:

• To evaluate the accuracy of different rules for determining visual acuity stability in amblyopia.
• To compare false-positive and false-negative rates for VA stability across various measurement and analysis methods.

Main Methods:

• Simulated observed VAs, including measurement error, were compared to simulated true VAs.
• Six distinct rules for assessing VA stability were tested, utilizing single or test/retest measurements over two or three visits, with or without averaging.
• Four amblyopia profiles (stable or improving VA) were modeled for patching and spectacle treatments.

Main Results:

• When true VA was stable, false-negative rates for stability ranged from 26% to 67%.
• When true VA was improving, false-positive rates for stability ranged from 0% to 38%.
• Averaging two VA tests per visit reduced false-positive rates but slightly increased false-negative rates compared to single measurements.

Conclusions:

• The choice of rule for determining VA stability impacts clinical and research outcomes.
• A lower false-negative rate is preferred when considering less desirable treatments, while a lower false-positive rate is better for accurately classifying improving VA.