A Virtual Reality Simulated Alternate Cover Test to Evaluate Adults with Strabismus

Area of Science:

• Ophthalmology
• Medical Technology
• Vision Science

Background:

• Precise strabismus measurement is crucial for adult strabismus diagnosis and management.
• Standard alternate cover test (ACT) has limitations in accuracy.
• Virtual reality (VR) presents a potential solution to improve strabismus measurement.

Purpose of the Study:

• To evaluate the performance of a VR-simulated ACT in adults with strabismus.
• To compare VR-based strabismus measurements with standard ACT results.
• To assess the correlation and agreement between VR and ACT measurements.

Main Methods:

• Prospective cohort study involving adults (≥18 years) with manifest strabismus (≥5 PD).
• Participants underwent VR-simulated ACT with eye-tracking (Olleyes VisuALL) and standard ACT by a masked pediatric ophthalmologist.
• Bland-Altman plots, ICC, and Spearman correlation analyzed agreement and association.

Main Results:

• VR measurements showed good correlation with ACT at distance (ICC=0.78) and moderate correlation at near (ICC=0.57).
• VR tended to overestimate smaller deviations and underestimate larger ones.
• Agreement was maintained in patients with deviations ≥10 PD (distance ICC=0.72, near ICC=0.64).

Conclusions:

• VR-simulated ACT demonstrates good correlation with standard strabismus measurements, particularly at distance.
• The technology shows promise for strabismus assessment in adults, despite variability in larger deviations.
• VR with eye-tracking technology is a viable tool for evaluating adult strabismus.