Development Of A Diplopia-testing Device Based On Virtual Reality Technology And Analysis Of Diplopia In Orbital Blowout Fractures

Objective:Binocular diplopia detection system（Virtual Reality Test,VRT）is constructed based on virtual reality（Virtual Reality,VR）technology,and compared with Hess screen detection and red glass diplopia detection test,to provide theoretical and practical basis for the application of VR technology in clinical diplopia detection.Methods:Firstly,the VRT software system was built,and the VRT front-end project and model were created by using Unity engine.Dynamically write Unity added,deleted,changed and checked the XML file,and checked the BUG,after the test was complete,confirmed that it was correct,and converted it to VR mode.Create a project on the PC side,place UI and add code,and read the local XML user information file.The VRT hardware system was a head-wearing HTC Vive head display device,and the VRT run on Steam VR.The detection beacon appeared on the plane with different distances from the patient’s eyes at different distances of 1m,3m and 5m,and moved around 8 diagnostic eye positions to detect and determine the positive areas of diplopia.Finally,the degree of diplopia was quantified by the positive angle of diplopia.Next,patients with orbital blowout fracture（Orbital blowout fracture,BOF）who were treated in the Department of Orbital Diseases and Ophthalmology,the second Hospital of Jilin University from September 2021 to December 2021 were collected.VRT diplopia detection system was used to quantitatively evaluate diplopia in orbital blowout fracture.At the same time,the sensitivity,stability and detection time of diplopia detection by VRT,Hess screen and red glass test were compared and analyzed.Results:We have successfully constructed the VRT software detection system,and used the head-wearing HTC Vive device to form the VRT diplopia detector.The sensitivity of VRT,Hess screen and red glass test was 95.12%,87.80% and 68.29% respectively,and the average detection time of VRT,Hess screen and red glass test was 2.65±0.52,2.17±1.23 and 5.34±0.25 min,respectively.The stability of VRT for diplopia test（ICC=1.00）was better than that of Hess screen test（HAR ICC=0.974;Hess score ICC=0.960）and red glass test（ICC=0.972）,and the result of VRT was positively correlated with Hess score（r=0.681,P < 0.05）,negatively correlated with HAR（r=-0.742,P<0.05）,and also correlated well with red glass test（r=0.488,P<0.05）.The results of VRT in binocular diplopia group were significantly different from those in healthy group（P<0.05）.The VRT system had good specificity for diplopia detection.Conclusion:It is proved that the quantitative detection of diplopia can be completed by using VRT system.The comprehensive performance of VRT is better than the current clinical Hess screen detection and red glass test diplopia detection methods,with good stability,high sensitivity,a wide range of visual field and superior detection time,and the detection results are not affected by head movement.In addition,VRT can use virtual environment to detect and evaluate diplopia at different spatial distances.This study provides a practical and theoretical basis for the application of VR technology in clinical diplopia detection.