An objective VER assessment of visual acuity compared with subjective measures

Area of Science:

• Ophthalmology
• Neuroscience
• Visual Science

Background:

• Assessing visual acuity is crucial for diagnosing and monitoring visual impairments.
• The transient visually evoked response (VER) is a non-invasive electrophysiological method to evaluate visual pathway function.
• Current VER methods may have limitations in accurately assessing a wide range of visual acuities.

Purpose of the Study:

• To optimize the estimation of visual acuity using pattern reversal transient visually evoked response (VER).
• To establish a reliable protocol for VER-based visual acuity assessment across different acuity levels.

Main Methods:

• Visual acuity was measured by analyzing the amplitude of the transient VER wave.
• Pattern reversal stimuli with check sizes of 5.5, 7.5, 8.5, and 9.5 min arc were employed.
• A threshold of 1.5 microV amplitude was used to determine the adequacy of the VER response.

Main Results:

• The 5.5 min arc check size effectively reflected visual acuity in high-acuity subjects.
• However, the 5.5 min arc check often failed to elicit a VER in low-acuity individuals.
• A proposed protocol utilizes the 5.5 min arc check for adequate responses and the 9.5 min arc check for insufficient responses to predict visual acuity.

Conclusions:

• A dual-check size approach (5.5 and 9.5 min arc) enhances the reliability of VER-based visual acuity estimation.
• This method improves the accuracy of visual acuity assessment, particularly in individuals with lower visual acuity.
• The proposed protocol offers a more robust electrophysiological tool for clinical visual acuity testing.