Predicting Post-Traumatic Stress Disorder Treatment Response Using Heart Rate Variability to Virtual Reality Environment and Modified Stroop Task: An Exploratory Study.

Predicting treatment response can inform treatment decisions, expectations, and optimize use of mental health treatment resources. This study examined heart rate (HR), heart rate variability (HRV), and a modified Stroop task (mStroop) to predict post-traumatic stress disorder (PTSD) treatment response. We report on an observational, longitudinal study with 45 U.S. veterans in outpatient PTSD care, who had deployed to Iraq or Afghanistan. HR and HRV were collected before, during, and after virtual reality (VR) combat and civilian scenes. HRV recovery was defined as HRV after a 3-minute VR simulation minus HRV during a VR scene. mStroop threat variables included index scores for combat and general threat. Self-report data were collected at baseline and 6 months later. The outcome variable was the 17-item Clinician Administered PTSD Scale (CAPS). Controlling for baseline CAPS and number of combat experiences, the following baseline HRV recovery variables were significant predictors of 6-month CAPS: standard deviation of normal beat to beat interval (SDNN) after combat scene minus SDNN during combat scene and low-frequency (LF HRV) after civilian scene minus LF during civilian scene. HRV at rest, HR reactivity, HR recovery, and mStroop scores did not predict treatment response. In conclusion, HRV recovery variables in the context of a standardized VR stressor were significant predictors of PTSD treatment response after controlling for baseline CAPS and number of combat experiences. The direction of this relationship indicates that greater baseline HRV recovery predicts lower 6-month PTSD symptom severity. This was an exploratory study in need of replication.

Virtual Reality Visual Perceptual Plastic Training Promotes Retinal Structure and Macular Function Recovery in Glaucoma Patients.

Twenty-seven glaucoma patients (54 eyes in total) with well-controlled intraocular pressure were trained with binocular virtual reality visual software for 3 months to investigate whether virtual reality visual perceptual plastic training promotes macular retinal structure and macular function recovery in glaucoma patients. The thickness of peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell layer-inner plexiform layer (mGCIPL), and mean macular sensitivity (mMS) were evaluated 3 months after training. The mean value of pRNFL thickness in glaucoma patients did not change significantly (Z = 0.642, p = 0.521), nor did the mean value (t = 1.916, p = 0.061) and minimum value (Z = 1.428, p = 0.153) of mGCIPL after 3 months. However, the significant increases were found in superior temporal mGCIPL thickness (t = 2.430, p = 0.019) as well as superior mGCIPL thickness (t = 2.262, p = 0.028). Additionally, the mMS was increased (Z = 2.259, p < 0.05), with the inferior square to be a more pronounced mMS increase (Z = 2.070, p = 0.038). In conclusion, virtual reality visual perceptual plastic training can increase the thickness of retinal ganglion cells complexes in the macular area of glaucoma patients and improve the macular function of the corresponding area. Clinical Trial registration number: ChiCTR1900027909.

Digital Therapy for Visual Acuity and Binocular Function in Children with Anisometropic Amblyopia.

Amblyopia affects development of children's monocular vision and binocular function and becomes a largely intractable problem with increasing aging. This study is to investigate the binocular function and evaluate efficacy of digital therapy in children 8-13 years of age with anisometropic amblyopia. The patients in the digital therapy group performed the training with the digital amblyopia therapeutic software. The visual acuity and binocular function (perceptual eye position [PEP], suppression, and stereopsis) were examined at the first visit and 3-month post-treatment. Twenty-three cases in the control group and 25 cases in the digital therapy group were enrolled. The results revealed that 3-month digital therapy can effectively improve corrected distance visual acuity (CDVA) and improve the binocular function, including PEP, suppression, and second-order stereopsis in children with anisometropic amblyopia, 8-13 years of age. Digital therapy for amblyopia can effectively improve monocular CDVA of amblyopic eyes and binocular function in older children with anisometropic amblyopia.

Exploring the Relationship Between Binocular Imbalance and Myopia: Refraction with a Virtual Reality Platform.

To explore the relationship between binocular imbalance (BI) and the abnormal development of binocular refraction. BI data were collected by enrolling the first 1,000 adolescents and children aged 6-18 years in Shenzhen Eye Hospital from April 2020 to January 2021. In this cross-sectional study, the imbalance value (IV) did not show a statistical correlation with the spherical equivalent (SE) (oculus dexter [OD]: r = 0.022, p = 0.586; oculus sinister [OS]: r = -0.021, p = 0.606), and had little correlation with the uncorrected visual acuity (VA) (OD: r = -0.084, p = 0.039; OS: r = -0.034, p = 0.408). The proportion of binocular contrast imbalance (BCI) (the absolute value) maintained the highest level (from 54.42 to 79.17 percent) with the increase of bilateral SE difference in the four subcategories (binocular balance, monocular suppression, binocular rivalry, and BCI). From -100 to +100 of IV, the SE of the left eye tends to increase negatively when compared with the right eye (from -95 < IV ≦ -80, SE difference = -0.83 ± 1.58, to -20 < IV ≦ -10, SE difference = -0.14 ± 0.61; from 10 ≦ IV <20, SE difference = -0.05 ± 0.80, to 80 ≦ IV <95, SE difference = 1.48 ± 2.77). BI widely exists within the general pediatric population. The BI did not show significant correlation with the unilateral eye refractive state and the VA. However, the BI may be accompanied by imbalanced development of the eye refractive system. Furthermore, the SE of the dominant eye (from the prospective of BI) tends to be more negative than that of the opposite eye as the value increases. Clinical Trial Registration number: ChiCTR2100045457.

Preliminary Study of Short-Term Visual Perceptual Training Based on Virtual Reality and Augmented Reality in Postoperative Strabismic Patients.

The study aimed to explore the potential effect of short-term visual perceptual training based on virtual reality (VR) and augmented reality (AR) platforms in postoperative strabismic patients. We enrolled 236 postoperative strabismic patients, among whom 111 patients received VR-based training, and 125 patients received AR-based training. The stereoacuity of 1.5 m and dynamic stereopsis were improved by VR training; meanwhile, AR training exhibited more improvement in stereoacuity of 0.8 and 1.5 m, dynamic and coarse stereopsis. It was suggested that the visual perceptual training based on VR and AR technology can be potentially applied in postoperative strabismus treatment to promote the recovery of binocular vision.

Exploring the use of virtual reality to manage distress in adolescent patients in emergency departments: A feasibility study.

OBJECTIVE: The present study aimed to explore the feasibility and potential benefits of deploying virtual reality (VR) for adolescents in the ED. METHODS: This multi-centre study was undertaken in paediatric and adult EDs in two university teaching hospitals. Twenty-six participants who had voluntarily attended the ED received the VR intervention. Pre- and post-measures assessing changes in state anxiety, stress and affect, and physical biomarkers were obtained. RESULTS: The use of VR intervention was associated with significant reductions in distress (Short State Stress Questionnaire - Distress Subscale; t = 4.55, P < 0.001) and negative affect (the International Positive and Negative Affect Scale - Short Form version; t = 4.99, P < 0.001). Most participants chose 'Netflix' as their content of choice. The technology was well received by the participants with subjective reports indicating that receiving VR intervention was 'insanely cool', 'takes you away from what's actually happening' and some participants felt 'privileged to get this experience in a hospital'. CONCLUSIONS: VR technology can effectively be used in EDs to assist adolescents and young adults better manage their distress and take steps towards activating more self-control mechanisms that will in turn allow for more meaningful engagements to be established with health clinicians. This technology has broad implications for reducing distress in adolescents in a variety of clinical contexts.

Combat-Related Post-traumatic Stress Disorder: A Case Report of Virtual Reality Graded Exposure Therapy With Physiological Monitoring in a U.S. Navy Officer and a U.S. Army Officer.

The U.S. Department of Defense (DoD) and the Department of Veterans Affairs (DVA) seek to enhance the efficacy of treatments for warriors with post-traumatic stress disorder (PTSD) secondary to their combat deployments to Iraq and/or Afghanistan. Virtual Reality Graded Exposure Therapy (VR-GET) with arousal control has shown particular promise in reducing the symptom severity of PTSD in combat veterans. In this report, we describe the outcome of VR-GET for the treatment of combat-related PTSD in two combat veterans, neither of whom had received treatment for PTSD in the initial years after their return from combat duty.

The Effectiveness of Binocular Virtual Reality Training on Repairing Visual Field Defect of Glaucoma.

Visual field defect caused by glaucoma seriously affects the quality of life of patients, and clinically, this type of visual field defect has been considered to be irreversible. The aim of this study is to use binocular virtual reality training (VR training) to repair visual field defect in glaucoma patients, improve the quality of life of patients, and provide a new therapeutic strategy for the rehabilitation of glaucoma. Seventy glaucoma patients (median 56, range 15-84 years) were recruited and divided into control and training groups. Fifty-four patients' data were analyzed. The training group (n = 30) received binocular VR training for 3 months. The control group (n = 24) maintained the conventional treatment without any other intervention. Their visual field index (VFI) and mean defect (MD), and retinal nerve fiber layer average thickness (RNFL) and ganglion cell layer average thickness (GCL) average thickness before training and during followup were analyzed. In the training group, the VFI value (Z = 3.277; p = 0.001) and MD value (Z = 3.913; p < 0.0001) were significantly improved after 1 month of training. After 3 months of training, the VFI value (Z = 3.761; p < 0.0001) and MD value (Z = 3.133; p = 0.002) were significantly improved. There was no significant difference with the changes of average thickness of RNFL (p = 0.350) and GCL average (p = 0.383) after 3 months of training; whereas in the control group, except for a further reduction in GCL average thickness (Z = 3.158; p = 0.002) compared with the baseline data, the other followup data were not statistically significant compared with the baseline data. Our data suggested that binocular VR training can significantly improve the visual field defect of glaucoma patients but warrants further study with large sample size. Clinical Trail registration number: ChiCTR1900027909.

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.

The Study of Perceptual Eye Position Examination and Visual Perceptual Training in Postoperative Intermittent Exotropes.

The aim of this study was to investigate perceptual eye position (PEP) and to evaluate the effect of dichoptic visual perceptual training in postoperative intermittent exotropia [X(T)]. We enrolled 30 non-strabismus children (control group) and 54 postoperative X(T) children [divided into training group (33 patients) and non-training group (21 patients)]. All subjects received measurements of PEP, and the postoperative X(T) children were measured both in the third postoperative day and the third postoperative month. All patients in training group received 3-month dichoptic visual perceptual training based on a unique virtual reality platform. The results showed that the postoperative X(T) children with normal eye position still had an abnormal PEP. After a period of visual perceptual training, the PEP pixels in postoperative children dramatically decreased. The results revealed that PEP could evaluate fixation disparity and binocular visual function perceptively and precisely, and the dichoptic visual perceptive training may rebuild binocular visual function.

Individualized Visual Reality Training Improves Visual Acuity and Visual Field Defects in Patients with Glaucoma: A Preliminary Study Report.

To explore whether individualized visual training improves the visual acuity and visual field defects of patients with glaucoma. Patients with established primary glaucoma who visited the glaucoma clinic of Beijing Shijitan Hospital, Capital Medical University from January 2018 to April 2018 were recruited. The binocular visual perception examination was performed by using the visual perception examination system, and a personalized training program was developed according to the relevant threshold conditions between the eyes of the patients. The binocular visual perception training session for 20 minutes for two sessions was completed at home by using a virtual reality helmet. The visual function, intraocular pressure, and Octopus visual field were examined, before and at the first month and the third month after training. Seven patients completed the study. None of the seven patients has fine stereopsis, four of them have large stereopsis, and two patients are without large stereopsis. The visual acuity at 3 months after training was significantly improved compared with that before training. The mean defect value after 1 month of training was significantly lower than that before training, and it was further decreased after 3 months. Similarly, the mean sensitivity value was significantly increased in both follow-ups after training. There was no significant difference in loss variance after 1 and 3 months of training when compared with that before training (p > 0.05). Our small prospective observational study indicated that individualized visual perception training can improve the visual function and improve the visual field in patients with glaucoma, and a large sample size study is warranted to further assess the value of this novel treatment.

Virtual Reality Air Travel Training Using Apple iPhone X and Google Cardboard: A Feasibility Report with Autistic Adolescents and Adults.

Rapid rises in autism diagnoses are increasing the demand for effective services and straining service providers. When individuals on the autism spectrum turn 18, they are faced with even greater barriers to services, since many services are delivered in school settings. Thus, there is a need for more accessible tools that teach daily life and communication skills to autistic adolescents and young adults. The current project reports findings from a pilot study using virtual reality (VR) to teach air travel skills to autistic young adults. The authors repurposed a virtual airport environment previously used to treat fear of flying for this study. Seven participants on the autism spectrum viewed a 5-minute virtual airport simulation with an overlaid narrative script using an iPhone X® and Google Cardboard® device once per week for 3 weeks. Researchers collected measures of attentiveness, language function, activity comprehension, and clinical observations on how participants interacted with the technology. Analyses revealed improvements in attentiveness, certain language functions such as labeling vocabulary, and activity comprehension in most participants. Clinical observations revealed acceptability of this technology and its capability to serve as an appealing media to deliver interventions. Thus, it is feasible to apply mobile VR trainings with autistic adolescents and young adults. We discuss ways to improve the pedagogical approach of VR-enhanced interventions in light of these findings. In the future, we plan to develop and test more virtual environments that address the needs of young adults on the autism spectrum, such as interview training and independent living skills. Lay summary: Why was this virtual reality air travel training program developed?: Each year, more and more people travel via airplane. Long lines, unexpected changes and other stressors can make air travel overwhelming and difficult, particularly for autistic people. Our goal was to develop and pilot test a program to help autistic adults learn air travel skills without needing to physically enter an airport.What does the virtual reality air travel training program do?: Our virtual reality air travel training (VR-ATT) program presents a virtual simulation of the steps that travelers go through in an airport. It guides users through entering, checking in, navigating security, waiting at the departure gate, and boarding. VR-ATT also contains a narrative to guide users by highlighting important information such as: "Look, there's the ticket counter. Let's check in with the attendant." This script was based on social stories, which are often used to help individuals on the autism spectrum learn communication and social interaction strategies. Seven autistic adolescents and adults participated in our program. They watched the VR-ATT simulation on an iPhone X® and Google Cardboard® two to three times over the course of 3 weeks. Google Cardboard is an inexpensive virtual reality (VR) headset.How did the researchers evaluate the VR-ATT program?: We evaluated the program in three ways. First, we asked each participant to retell the sequence of events of the simulation. In other research studies, participants who retold what they watched showed a greater ability to apply the skill to the real world. Second, we tracked how and what types of language participants used. Third, we measured if participants could independently view the VR-ATT simulation without side effects such as dizziness or cybersickness (common side effects of VR viewing). This helps us understand the feasibility and acceptability of using VR with autistic individuals.What were the early findings?: Early findings suggest that autistic individuals are accepting of the iPhone and Google Cardboard VR viewing method. They also provide preliminary support for the ability of the program to promote improvements in functional language skills such as labeling vocabulary, which helps individuals interact and navigate busy environments, such as an airport. Finally, the findings suggest that participants can accurately retell the sequence of events in the virtual simulation.What were the weaknesses of this project?: One weakness was that researchers could not test how participants transferred the skills they learned in the virtual training to a real-world airport. Another weakness is the small sample of participants. Finally, not every participant completed all three training sessions, making it difficult to draw precise conclusions about the program's acceptability and success.What are the next steps?: Future studies should include a larger number of participants, a real-world test, changes to the virtual simulation to encourage more language use and interaction with virtual characters, and use more accurate measurement materials.How will this work help autistic adults now or in the future?: This air travel program may someday help autistic people learn what to expect and how to communicate in a busy airport setting. This program also highlights that new technology, such as VR, could potentially improve access to services and help more people in need in the future.

Virtual Reality Assessment Reveals Myopic Regression After ICL Implantation in High Myopia.

PURPOSE: To investigate the correlative factors of vision regression after Implantable Collamer Lens (ICL) surgery from the perspective of binocular vision and to develop a predictive model for the refractive change over the long term. METHODS: This was a prospective study of 30 subjects (60 implants), who underwent ICL surgery at Guangdong General Hospital. Corrected distance visual acuity, uncorrected distance visual acuity, spherical equivalent (SE), axial length and binocular examination using virtual reality were analyzed before, 1 month and 1 year after the surgery. RESULTS: Mean SE was (-12.01 ± 0.86) D preoperatively, (-0.44 ± 0.13)D 1 month postoperatively and (-0.97 ± 0.15)D 1 year postoperatively. The average regression 1 year postoperatively (-0.53 ± 0.25D of SE) was significant (P = 0.01). Mean axial length at the base line and 1 year after the surgery was (28.35 ± 0.39) mm and (28.91 ± 0.57) mm. The regression was correlated with the binocular equilibrium difference (r = 0.553, P = 0.002), and the degree of perceptual eye position shift, especially the horizontal shift (r = -0.620, P = 0.000). The important variables relevant to myopic regression were preoperative horizontal perceptual eye position shift (B = -0.007, P = 0.001) and binocular equilibrium difference (B = 0.146, P = 0.012). CONCLUSION: Perceptual eye position deviation and the binocular equilibrium difference could cause binocular gazing instability, and the unstable retinal image created a 'micro retinal-defocus phenomena', leading to an elongation of the axial length and resulting in myopic regression after ICL surgery.

Virtual Reality Air Travel Training with Children on the Autism Spectrum: A Preliminary Report.

Autism spectrum disorder (ASD) is categorized by deficits in social communication and interaction, alongside repetitive, restrictive behaviors or interests (RRBIs). Previous research supports the efficacy of virtual reality (VR) to train a variety of specific skills (i.e., riding a bus or crossing the street) as well as more complex social skills, such as emotion recognition and functional communication. The present reports the implementation of a VR-based air travel functional communication activity in five children diagnosed with ASD. Using an iPhone X and Google Cardboard device, researchers delivered the VR intervention once per week for 3 weeks to each participant. During these interventions, researchers measured activity completion ability on a 4-point scale. At week 4, all children participated in a real-world air travel rehearsal at the San Diego International Airport. Parents were asked to rate their child's air travel abilities before week 1 and after week 4. All children improved their air travel skills from pre- to postintervention, reflected in both the researchers' and parents' observations. All children navigated the real-world airport under their own power. This preliminary report suggests the efficacy of VR to teach basic air travel skills to young children diagnosed with autism. Clinician observations regarding attention to the VR and strategies for helping participants accept the intervention technique are discussed. Future iterations of this program will require larger sample sizes and more robust clinical measurements-such as communication samples and physiological monitoring.

Augmented Reality: Poised for Impact.

Though augmented reality (AR) has existed for decades, the technology's full impact is just beginning to become apparent. Since its inception, AR has shown significant promise for use in a wide variety of fields, including education, entertainment, art, and the sciences. This special issue focuses specifically on the impact of this unique technology on healthcare, particularly the areas of clinical training, patient education and treatment, and its use as a robust assessment tool. Now that technology is catching up with imagination, researchers are able to investigate these applications in earnest.

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.

Physiological Monitoring During Augmented Reality Exercise Confirms Advantages to Health and Well-Being.

Augmented reality (AR) is a versatile tool that is changing the way we interact with the world. One way is through exergaming, integrating AR, and gaming with traditional exercise programs. This study aimed to test three different AR systems to determine their ability to elicit physiological responses similar to those experienced while exercising or performing rehabilitation exercises. The systems tested included a head-mounted display experience (Teapots), a Sony EyeToy game (Slap Stream), and a prototype of a PC-camera-based system (Drums). Physiological recordings show that Slap Stream and Drums produced significant increases (p < 0.05) in heart rate (HR) and skin conductance, and all three games produced nonsignificant increase in respiratory rate. Of the three games, Slap Stream produced the highest rates of low- (∼28 percent), moderate- (17 percent), and high-intensity (∼22 percent) HRs. This study successfully showed that inexpensive easy-to-use AR systems can effectively contribute to exercise programs. Future game design recommendations, including feedback, mixed reality, and stress tracking, are discussed.

Pain Distraction During Ambulatory Surgery: Virtual Reality and Mobile Devices.

Virtual reality (VR) pain distraction has been applied across medical, surgical, and behavioral healthcare domains, marking a shift in pain attenuation practices. However, there is little research that has been performed to compare the efficacy of traditional head-mounted displays (HMDs) versus portable VR devices. The present study evaluated 44 outpatients in need of lipoma resection. Randomized into two groups-HMD versus mobile phone VR-participants navigated pain distraction virtual environments while undergoing surgery. Vital signs and subjective pain measurements via a visual analog scale were taken before, during, and after the surgery. Results indicate that the HMD group reported greater pain reduction than the Mobile group. Overall, this study points to the efficacy of nonpharmacological pain attenuation practices. Although both systems reduced pain during surgery, the clinically validated VR environments seen in the HMD group were more effective. This study does show that inexpensive solutions can work in surgical settings. Future research should be performed to identify the most effective VR pain distraction systems.

Heart Rate Variability and Cognitive Bias Feedback Interventions to Prevent Post-deployment PTSD: Results from a Randomized Controlled Trial.

Introduction: There is a long history of pre-deployment PTSD prevention efforts in the military and effective pre-deployment strategies to prevent post-deployment PTSD are still needed. Materials and Methods: This randomized controlled trial included three arms: heart rate variability biofeedback (HRVB), cognitive bias modification for interpretation (CBM-I), and control. The hypothesis was that pre-deployment resilience training would result in lower post-deployment PTSD symptoms compared with control. Army National Guard soldiers (n = 342) were enrolled in the Warriors Achieving Resilience (WAR) study and analyzed. The outcome was PTSD symptom severity using the PTSD Checklist - Military version (PCL) measured at pre-deployment, 3- and 12-month post-deployment. Due to the repeated measures for each participant and cluster randomization at the company level, generalized linear mixed models were used for the analysis. This study was approved by the Army Human Research Protection Office, Central Arkansas Veterans Healthcare System Institutional Review Board (IRB), and Southeast Louisiana Veterans Health Care System IRB. Results: Overall, there was no significant intervention effect. However, there were significant intervention effects for subgroups of soldiers. For example, at 3-months post-deployment, the HRVB arm had significantly lower PCL scores than the control arm for soldiers with no previous combat zone exposure who were age 30 and older and for soldiers with previous combat zone exposure who were 45 and older (unadjusted effect size -0.97 and -1.03, respectively). A significant difference between the CBM-I and control arms was found for soldiers without previous combat zone exposure between ages 23 and 42 (unadjusted effect size -0.41). Similarly, at 12-months post-deployment, the HRVB arm had significantly lower PCL scores in older soldiers. Conclusion: Pre-deployment resilience training was acceptable and feasible and resulted in lower post-deployment PTSD symptom scores in subgroups of older soldiers compared with controls. Strengths of the study included cluster randomization at the company level, use of iPod device to deliver the resilience intervention throughout the deployment cycle, and minimal disruption of pre-deployment training by using self-paced resilience training. Weaknesses included self-report app use, study personnel not able to contact soldiers during deployment, and in general a low level of PTSD symptom severity throughout the study. In future studies, it would important for the study team and/or military personnel implementing the resilience training to be in frequent contact with participants to ensure proper use of the resilience training apps.