Mixed Reality Glasses Image Translocation for Binocular Diplopia.

Background

The traditional treatment of binocular diplopia includes patching, prisms, and strabismus surgery. We investigate if image translocation with mixed reality glasses (MRG) can be applied to binocular diplopia rehabilitation.

Methods

Adult volunteers with binocular diplopia in the primary position presenting to the Eye Institute of Alberta underwent visual acuity and alternate prism cover testing. Custom software was developed for the HoloLens 2 MRG to transpose the image seen by the fixating eye to the strabismus angle of nonfixating eye. The transposition could be adjusted for vertical, horizontal, and torsional rotations and size. Participants wore the MRG in the primary position of a 6 m examination lane for a maximum of 30 minutes. A bipolar linear visual analog scale from 0 to 100 was used to rate the satisfaction with the MRG, with a score of 50 being neutral.

Results

There were 42 participants of median age of 46.5 years of age, 25 (60%) of whom were female. Twenty-three patients (55%) had horizontal strabismus, 9 (21%) had vertical strabismus, and 10 (24%) had combined horizontal and vertical strabismus. Twenty-nine (69%) of the participants found the MRG helpful for diplopia with an average satisfaction rating of 83.9% ± 12.0%. There was a statistically significant association between the satisfaction score and the magnitude of the strabismus (odds ratio 0.934 (0.879-0.993), P = 0.029) but not with age, sex, acuity, or strabismus direction.

Conclusions

This prototype MRG image translocation software was helpful to 69% of patients with binocular diplopia, but limited by large angle strabismus because of the limited instrument field of view. This application may become mainstream when MRG becomes more compact and powerful, with wider fields of view.