Virtual reality-based Harms tangent screen test for strabismus measurement

What is known The incidence of neurogenic diplopia increases in the ageing population. The Harms tangent screen test (HTS) reliably measures subjective ocular deviations in patients with diplopia. The HTS requires staff well-trained in orthoptics limiting its use. What is new A novel virtual reality-based tangent screen test (VTS) enables measurement of horizontal, vertical and torsional ocular misalignment and shows a good comparability to the HTS. VTS uses commercially available head-mounted-display and controller, and specifically developed software, requires less time than HTS and allows automatic documentation. VTS administration does not require orthoptic training and can eventually be implemented in a clinical setting to provide a wider availability of subjective squint angle measurements.