ABSTRACT
Purpose of Study: Assessment of an individual's postural stability serves as an indirect measure for both physiological and biomechanical stresses placed on an individual. More recently, some individuals after COVID-19 (SARS-CoV-2) infection have been identified with neurological complaints (Post-Acute Sequelae of Covid - PASC). These individuals can also be predisposed to decreased postural stability and an increased risk for falls. The purpose of the project was to incorporate two different wearable technology (virtual reality (VR) based virtual immersive sensorimotor test - VIST and pressure senor-based smart sock) to assess postural stability among healthy and individuals with PASC to quantify the overall status of the postural control system. Methods Used: All methods were conducted based on the University's Institutional Review Board (IRB# 21-296) with informed consent. A total of 12 males and females (six healthy and six with self-reported complaints of PASC) have completed the study so far. All participants were tested using the VIST, while standing on a force platform and wearing the smart sock simultaneously. The (VIST uses a VR headset and proprietary software to test an individual's integrated sensory, motor, and cognitive processes through eight unique tests (smooth pursuits, saccades, convergence, peripheral vision, object discrimination, gaze stability, head-eye coordination, cervical neuromotor control). Center of pressure (COP) data from force platform and pressure sensor data from the smart socks were used to calculate anterior-posterior and medial-lateral postural sway variables. These postural sway variables were analyzed using an independent samples t-test between the healthy and PASC groups at an alpha set at 0.05. Summary of Results: Significant differences (p < 0.05) between healthy and individuals with PASC with anteriorposterior and medial-lateral postural sway variables derived from COP measures, with individuals with PASC exhibiting significantly greater postural sway compared to healthy individuals in all eight tests of the VIST. The measures from the smart sock, while not statistically significant, exhibited the same findings of increased postural sway in individuals with PASC compared to healthy individuals. Conclusion(s): Findings from the current analysis revealed that individuals with PASC demonstrated significantly worse postural control compared to the healthy, when challenged with various sensorimotor tests in VIST, suggesting that postural control is compromised due to PASC. While not statistically significant due to a lower sample size, the measures from smart sock also indicated the same findings of the COP measures, suggesting a promising use of wearable technology in postural control assessments. In addition to other neurological signs and symptoms of PASC, assessment of postural stability using the VIST can provide more detailed clinical measures for diagnosis, treatment, and prognosis assessments. Copyright © 2023 Southern Society for Clinical Investigation.
ABSTRACT
Purpose : 57.5 million people worldwide are affected by glaucoma. However, 50% of those with glaucoma are unaware, and 80% of those identified for follow-up in community screenings (CS) fail to do so. Current standards of visual field testing are usually limited to the clinic. As such, a wearable perimetry headset was used to perform Virtual Reality Visual Field Acuity (VRVFA) examination for suspected visual field loss in the community minimizing exposure to COVID-19 and the need for follow-up. Methods : 31 subjects from 4 CS were screened by an onsite certified telemedicine reader (CR) who considered family history, visual acuity, intraocular pressures, cup-to-disc ratio, nerve fiber layer defects, and ganglion cell complex captured by non-mydriatic photography and ocular coherence tomography (OCT-B). Cataracts were also graded. Supervised VRVFA testing with a multilingual Palmscan VF2000 Analyzer (Fig.1) was performed in 6 minutes on average. Eyes with fixation losses >20% or false positive/negative ratios >0.375 were excluded. Visual field index (VFI), mean deviation (MD), pattern standard deviation (PSD), and mean sensitivity (MS) from VRVFA were compared to CR glaucoma referral and cataract grading. Descriptive statistics, independent samples t-tests, and Mood's median tests were performed. Subjects with positive findings underwent same-day robotic glaucoma specialist telepresence evaluation. Results : 37 eyes from 31 subjects met inclusion criteria (mean age 51.42 ± 14.57 years, 56.76% male, 94.59% Hispanic). 7 (18.92%) eyes were referred for glaucoma evaluation. Glaucoma referrals had significantly different VFI (66.86% vs 86.40%, p=0.027), MD (-9.60 vs -4.04, p=0.031), and MS (19.94 vs 26.01, p=0.027) (Fig. 2). 30 (81.08%) eyes were 0-1+ in cataract grading, 5 (13.51%) were 2-3+, and 2 (5.41%) were intra-ocular lenses (IOL);respectively, these subgroups were not significantly different in VFI (84.20% vs 92.80% vs 35.00%, p=0.147), MD (-4.70 vs -2.11 vs -18.41, p=0.147), PSD (3.52 vs 2.25 vs 9.69, p=0.053), or MS (25.38 vs 27.75 vs 9.91, p=0.147) (Fig. 2). Conclusions : VRVFA testing yielded valuable information on the extent of vision loss as a supportive screening tool for glaucoma congruent with referrals. Expanded testing is needed. Future studies may evaluate VRVFA utility in evaluating other peripheral vision threatening diseases.