Binocular integration and stereopsis in children with television torticollis.

BACKGROUND: To observe the characteristics of binocular integration and stereopsis in children with television torticollis. METHODS: A retrospective study was carried out, where data were collected from 25 children with television torticollis as the disease group after refractive error correction and 25 normal children as the control group. A virtual reality system was used to assess and analyze the characteristics of binocular integration by a contrast balance test and binocular stereopsis. RESULTS: The 25 children in the disease group included 17 males and 8 females with an average age of 7.5 ± 1.9 years old and an average binocular spherical equivalent of - 0.35 ± 1.46D. The 25 children in the control group were also 17 males and 8 females with an average age of 7.3 ± 2.2 years old and the average binocular spherical equivalent of - 0.48 ± 0.93D. No significant differences were found in the horizontal bar contrast balance test between the 2 groups at near and far distances. Near-distance vertical bar contrast balance test was normal in 23 subjects and suppressed in 2 subjects in the control group, while it was normal in 13 subjects and suppressed in 12 subjects in the disease group, which showed a statistically significant difference (P = 0.002). Far distance vertical bar contrast balance test was normal in 24 subjects and suppressed in 1 subject in the control group, normal in 7 subjects and suppressed in 18 subjects in the disease group, showing a statistically significant difference (P = 0.000). All subjects in the 2 groups showed 100〞 as near distance stereoacuity. At far distance, the mean stereoacuity was 176.00〞 ± 92.56〞 in the control group, and 352.00〞 ± 270.99〞 in the disease group, with a statistically significant difference (P = 0.011). CONCLUSION: By using virtual reality technology, defects in binocular visual function were found in children whose television torticollis persisted after regular refractive error correction. Television torticollis may be associated with the deficit of binocular integration for vertical bars and far distance stereopsis.

Assessment of Binocular Imbalance with an Augmented Virtual Reality Platform in a Normal Population.

We examined and analyzed binocular imbalance in a group of randomly selected normal subjects with corrected visual acuity of 0.8 or more in both eyes without ocular diseases, by using augmented virtual reality system. This study will quantify the correlation between binocular imbalance in these normal subjects and various spatial frequencies and temporal frequencies in the integrated binocular stimulation mode. A retrospective study was carried out and data from 97 patients (51 males and 46 females) who were diagnosed with no eye diseases, and with corrected binocular visual acuity of 0.8 or more, were collected. Their binocular visual function, Hirschberg test refraction status, and binocular imbalance were assessed using the quantified visual perception stimulation mode in an augmented virtual reality platform. When normal subjects (with corrected binocular vision of 0.8 or more without ocular diseases) were assessed using the integrated binocular stimulation mode with different temporal and spatial frequencies, a gradual reduction of binocular imbalance could be observed when spatial frequencies were increased. When contrast balance was adjusted, binocular imbalance was more prevalent in the horizontal state compared with the vertical state. This was seen when patients were stimulated by different temporal frequencies in the virtual reality testing mode. 17.53% and 29.90% of participants reached complete binocular fusion under low temporal frequency stimulation and high temporal frequency stimulation, respectively, while binocular imbalance was found in 65.9% and 62.89% of participants who were stimulated, respectively, by low temporal frequency and high temporal frequency. In addition, 16.5% and 7.21% experienced severe binocular imbalance under low temporal and high temporal frequency stimulation, respectively. The integrated binocular stimulation mode under low temporal frequency was more sensitive in detecting binocular imbalance. The status of binocular balance in normal subjects was not the same when stimulated by the augmented virtual reality platform, as many showed varying degrees of binocular imbalance. The results from our clinical study demonstrate that integrated binocular stimulation with different spatial and temporal frequencies enables a more sensitive detection of binocular imbalance, making it a powerful new tool for the diagnosis and analysis of clinical binocular abnormalities. In addition, since more than half of the normal subjects (without eye diseases who has corrected vision of 0.8 or more) exhibited binocular imbalance in our study, we believe that this brief binocular imbalance is likely a transient physiological phenomenon, which is not pathological to visual acuity and function, and should only be seen as pathological when binocular imbalance is prolonged, causing functional deficits such as reading impairment.