Measuring visual information gathering in individuals with ultra low vision using virtual reality

Area of Science:

• Ophthalmology
• Vision Science
• Rehabilitation Medicine

Background:

• Individuals with ultra-low vision (ULV) have limited form vision but retain rudimentary visual capabilities.
• Existing clinical tests primarily assess form vision, failing to capture the functional visual abilities relevant to daily life for ULV individuals.
• There is a growing need for effective outcome measures in clinical trials for ULV, including those involving gene therapy, stem cell therapy, and visual prostheses.

Purpose of the Study:

• To develop and validate a novel set of virtual reality (VR) activities to assess visual performance in individuals with ULV.
• To evaluate the utility of this VR-based assessment as an outcome measure in clinical trials for ULV.

Main Methods:

• A set of 19 VR activities were developed, focusing on spatial localization/detection, motion detection, and direction of motion.
• Signal detection theory-based analysis of latent variables was employed to estimate item difficulty and person ability on a relative d' axis.
• The assessment was administered to a heterogeneous group of individuals with ULV.

Main Results:

• The developed VR activities spanned a range of difficulty levels (–1.09 to 0.39 in relative d').
• Individuals with ULV demonstrated a wide range of abilities (–0.74 to 2.2 in relative d'), highlighting the instrument's sensitivity.
• The study demonstrated the utility of the VR assessment as a viable outcome measure for clinical trials involving ULV.

Conclusions:

• The novel VR-based assessment effectively measures visual performance in individuals with ULV across a spectrum of abilities.
• This tool provides valuable insights into functional vision beyond form acuity, crucial for evaluating the efficacy of vision restoration interventions.
• The developed instrument shows promise as a standardized outcome measure for clinical trials aimed at improving vision in ULV populations.