We evaluated the effect of dichoptic visual training based on a unique virtual reality (VR) platform mounted display in patients with intermittent exotropia (IXT). A total of 25 IXT patients (8 men, 17 women) with a mean age of 12.3 years (range, 5-39 year) were recruited. The Hirschberg test, prism and alternate cover testing (with accommodative targets for fixation at 33 cm in all patients), perceptual eye position (PEP), and stereopsis were evaluated after 1, 3, and 6 months of dichoptic visual neuroplasticity training with a computer-controlled perceptual examination evaluation system. Data collected before and after training were evaluated using SPSS software. After 6 months of perceptual training, a new order stereopsis was established, and eye positions were improved in all 25 patients. After training for 1 and 6 months, the horizontal PEP pixels were much lower than those pretraining, respectively (Δ1-0 = -0.53, p = 0.028; Δ6-0 = -0.80, p = 0.018). There was no statistically significant difference between pretraining and 3 months after training in horizontal PEP (Δ3-0 = -0.29, p = 0.370). There was no significant difference between pretraining and post-training in vertical PEP (p > 0.05). There were significant differences between pretraining and post-training in the cornea's optical reflection and prism diopters (p < 0.01). Dichoptic visual neuroplasticity training based on a VR platform is an effective nonsurgical treatment in patients with IXT. With the VR treatment, the degree of strabismus and stereopsis was improved in IXT patients. Perceptual training with VR can remove obstacles in the visual processing channel and repair defects in visual function. The clinical manifestations of improvement were the decrease in the degree of strabismus and the re-establishment of stereopsis.
Keywords: intermittent exotropia; perceptual training; stereopsis; virtual reality.