VEP estimation of visual acuity: a systematic review

Area of Science:

• Ophthalmology and Neuroscience
• Visual electrophysiology
• Clinical assessment of vision

Background:

• Visual acuity is crucial for daily function.
• Objective measures are needed for individuals unable to perform behavioral tests.
• Visual evoked potentials (VEPs) provide an objective estimate of visual resolution.

Purpose of the Study:

• To systematically review VEP spatial frequency (SF) limits in humans.
• To assess the accuracy and precision of VEP SF limits as a measure of visual acuity.
• To collate VEP SF limit data across healthy and disordered populations.

Main Methods:

• Systematic review following PRISMA guidelines.
• Searched multiple databases for VEP and acuity-related terms.
• Extracted data on VEP SF limits, stimuli, recording/analysis techniques, and correlation with behavioral acuity.

Main Results:

• 155 studies included; VEP SF limits vary (15-40 cpd in healthy adults) based on methodology.
• VEP SF limits mature rapidly in infants, with differences from behavioral acuity decreasing over time.
• Relationship between VEP SF limits and behavioral acuity varies by condition, being less consistent for neurological/macular issues.

Conclusions:

• VEP SF limits are highly useful for objective acuity estimation, especially in pre-verbal children or those with impairments.
• Accurate interpretation requires age-stratified reference data and calibration with behavioral acuity.
• Future research should focus on faster, more robust VEP techniques.