Publications by authors named "Thomas Buckley"

302 Publications

Microperimetry Hill of Vision and Volumetric Measures of Retinal Sensitivity.

Transl Vis Sci Technol 2021 Jun;10(7):12

Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Biomedical Research Centre, Oxford, UK.

Purpose: Mean retinal sensitivity is the main output measure used in microperimetry. It is, however, of limited use in patients with poor vision because averaging is weighted toward zero in those with significant scotomas creating an artificial floor effect. In contrast, volumetric measures avoid these issues and are displayed graphically as a hill of vision.

Methods: An open-source program was created to manipulate raw sensitivity threshold data files obtained from MAIA microperimetry. Thin plate spline interpolated heat maps and three-dimensional hill of vision plots with an associated volume were generated. Retrospective analyses of microperimetry volumes were undertaken in patients with a range of retinal diseases to assess the qualitative benefits of three-dimensional visualization and volumetric measures. Simulated pathology was applied to radial grid patterns to investigate the performance of volumetric sensitivity in nonuniform grids.

Results: Volumetric analyses from microperimetry in RPGR-related retinitis pigmentosa, choroideremia, Stargardt disease, and age-related macular degeneration were analyzed. In simulated nonuniform testing grids, volumetric sensitivity was able to detect differences in retinal sensitivity where mean sensitivity could not.

Conclusions: Volumetric measures do not suffer from averaging issues and demonstrate superior performance in nonuniform testing grids. Additionally, volume measures enable detection of localized retinal sensitivity changes that might otherwise be undetectable in a mean change.

Translational Relevance: As microperimetry has become an outcome measure in several gene-therapy clinical trials, three-dimensional visualization and volumetric sensitivity enables a complementary analysis of baseline disease characteristics and subsequent response to treatment, both as a signal of safety and efficacy.
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http://dx.doi.org/10.1167/tvst.10.7.12DOI Listing
June 2021

A double-ratio method (DRM) to measure fast, slow and reverse sap flows.

Tree Physiol 2021 Jun 7. Epub 2021 Jun 7.

Department of Plant Sciences, University of California, Davis, Davis, CA, United States.

Sap velocity measurements are useful in fields ranging from plant water relations to hydrology at a variety of scales. Techniques based on pulses of heat are among the most common methods to measure sap velocity, but most lack ability to measure velocities across a wide range, including very high, very low and negative velocities (reverse flow). We propose a new method, the double-ratio method (DRM), which is robust across an unprecedented range of sap velocities and provides real-time estimates of the thermal diffusivity of wood. The DRM employs one upstream (proximal) temperature sensor and two downstream (distal) sensors to the source of heat. This facilitates several theoretical, heat-based approaches to quantifying sap velocity. We tested the DRM using whole-tree lysimetry in Eucalyptus cypellocarpa and found strong agreement across a wide range of velocities.
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http://dx.doi.org/10.1093/treephys/tpab081DOI Listing
June 2021

Effectiveness of a Computerized Cognitive Training Program for Reducing Head Impact Kinematics in Youth Ice Hockey Players.

Int J Exerc Sci 2021 1;14(1):149-161. Epub 2021 Apr 1.

Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA.

Cognitive training (CT) is an effective technique to improve neurological performance, but has not been investigated as a head impact primary prevention strategy. The purpose of this study was to investigate the CT's effectiveness in reducing head impact kinematics in youth ice hockey players. Twenty youth were divided into two groups: a CT and Control group. The CT group performed two 30-minute sessions of IntelliGym CT weekly for 20 weeks and the control group performed two 30-minute sessions weekly evaluating hockey videos. The dependent variables, number of head impacts, cumulative linear acceleration (CLA) and rotational acceleration (CRA) and mean linear and rotation peak acceleration, were compared with repeated measures ANOVAs, with post-hoc for main effect of time for each group, between the first and second half of the season. There were significant interactions for number of head impacts ( = 0.014) and CLA ( = 0.043) and post-hoc testing identified reductions in the second half of the season for the CT, but not control, group. There were no interactions for CRA, mean peak linear acceleration, and mean peak rotational acceleration. These preliminary results suggest CT may be an effective primary prevention strategy to reduce head impacts and cumulative linear acceleration in youth ice hockey players.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8136557PMC
April 2021

Psychological responses and coping behaviour of visiting family members during and following unplanned hospital admission.

J Clin Nurs 2021 May 24. Epub 2021 May 24.

University of Sydney, Sydney, Australia.

Aims: To describe the psychological symptoms and coping behaviours of visiting family members following the unplanned hospitalisation of their relative.

Background: Hospitalisation of a patient is recognised as a stressful time for visiting family members, who experience psychological morbidity and elevated health risk.

Design: This prospective longitudinal evaluation included 40 family members of patients with unplanned admission to coronary or intensive care. Assessments were conducted at 3 timepoints: in-hospital within 1 week of admission and again at 2 weeks and 3 months post-discharge. Measures included symptoms of anxiety, depression, and anger, coping strategies and social support. This paper adhered to STROBE guidelines.

Results: At the initial in-hospital assessment study participants reported higher anxiety, depression and anger symptoms levels compared to community matched control participants. Compared to in-hospital assessment, anxiety and depression levels were lower at 2 weeks and 3 months following hospital discharge. The use of active coping and the use of religion during early hospitalisation were associated with higher anxiety and depression symptoms at 3 months post-discharge. Conversely, use of instrumental support (getting help and advice from others), planning and venting during early hospitalisation were associated with lower depression symptoms at 3 months. Venting during the hospitalisation period was also associated with lower anxiety symptoms at 3 months.

Conclusion: Results demonstrate the significant psychological impact of unplanned hospitalisation on visiting family members both during and following hospitalisation. The finding that prolonged psychological response is associated with individual coping strategies employed in the early hospitalised period informs potential preventative approaches for family members at risk of prolonged psychological morbidity following hospitalisation of their loved one.

Relevance To Clinical Practice: The reported psychological impact of hospitalisation on family members provides a strong imperative for nurses and health professionals to provide early individualised support to reduce the risk of long-term psychological morbidity.
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http://dx.doi.org/10.1111/jocn.15858DOI Listing
May 2021

Low Luminance Visual Acuity and Low Luminance Deficit in Choroideremia and RPGR-Associated Retinitis Pigmentosa.

Transl Vis Sci Technol 2021 Feb;10(2):28

Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.

Introduction: Choroideremia and RPGR-associated retinitis pigmentosa (RP) are two distinct inherited rod-cone degenerations, where good visual acuity (VA) is maintained until late disease stages, limiting its usefulness as a disease marker. Low luminance VA and low luminance deficit (standard VA minus low luminance VA) may be more sensitive visual function measures.

Methods: Standard VA was obtained using Early Treatment Diabetic Retinopathy Study letter charts (Precision Vision, Bloomington, IL, USA). Low luminance VA was assessed using a 2.0-log unit neutral density filter, with the same chart setup, without formal dark adaptation. Mean central retinal sensitivity was assessed using MAIA microperimetry (Centervue SpA, Padova, Italy). Optical coherence tomography imaging was attained with Heidelberg Eye Explorer software (Heidelberg Engineering, Heidelberg, Germany).

Results: Twenty-four male participants with confirmed pathogenic RPGR mutations, 44 male participants with confirmed pathogenic CHM mutations, and 62 age-matched controls underwent clinical assessment prior to clinical trial recruitment. Low luminance VA was significantly reduced in both disease groups compared to controls. The low luminance deficit correlated with microperimetry retinal sensitivity and ellipsoid zone width. Eleven participants with moderate VA had poor low luminance VA (subsequently a large low luminance deficit), no detectable microperimetry sensitivity, and severely constricted ellipsoid zone widths.

Conclusions: Low luminance VA and subsequently low luminance deficit are useful markers of central macular visual function in both choroideremia and RPGR-associated RP, when standard VA is preserved.

Translational Relevance: Low luminance visual acuity and low luminance deficit are useful vision measures in two distinct rod-cone degenerations and may be useful in other retinal degenerations.
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http://dx.doi.org/10.1167/tvst.10.2.28DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7900861PMC
February 2021

Discriminative Validity of Vestibular Ocular Motor Screening in Identifying Concussion Among Collegiate Athletes: A National Collegiate Athletic Association-Department of Defense Concussion Assessment, Research, and Education Consortium Study.

Am J Sports Med 2021 May 12:3635465211012359. Epub 2021 May 12.

Department of Orthopedic Surgery, UPMC Sports Medicine Concussion Program, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.

Background: Vestibular and ocular motor screening tools, such as the Vestibular/Ocular Motor Screening (VOMS), are recognized as important components of a multifaceted evaluation of sport-related concussion. Previous research has supported the predictive utility of the VOMS in identifying concussion, but researchers have yet to examine the predictive utility of the VOMS among collegiate athletes in the first few days after injury.

Purpose: To determine the discriminative validity of individual VOMS item scores and an overall VOMS score for identifying collegiate athletes with an acute sport-related concussion (≤72 hours) from healthy controls matched by age, sex, and concussion history.

Study Design: Case-control study; Level of evidence, 3.

Methods: Participants (N = 570) aged 17 to 25 years were included from 8 institutions of the National Collegiate Athletic Association-Department of Defense CARE Consortium (Concussion Assessment, Research, and Education): 285 athletes who were concussed (per current consensus guidelines) and 285 healthy controls matched by age, sex, and concussion history. Participants completed the VOMS within 3 days of injury (concussion) or during preseason (ie, baseline; control). Symptoms are totaled for each VOMS item for an item score (maximum, 40) and totaled across items for an overall score (maximum, 280), and distance (centimeters) for near point of convergence (NPC) is averaged across 3 trials. Receiver operating characteristic analysis of the area under the curve (AUC) was performed on cutoff scores using Youden index () for each VOMS item, overall VOMS score, and NPC distance average. A logistic regression was conducted to identify which VOMS scores identified concussed status.

Results: A symptom score ≥1 on each VOMS item and horizontal vestibular/ocular reflex ≥2 significantly discriminated concussion from control (AUC, 0.89-0.90). NPC distance did not significantly identify concussion from control (AUC, 0.51). The VOMS overall score had the highest accuracy (AUC, 0.91) for identifying sport-related concussion from control. Among the individual items, vertical saccades ≥1 and horizontal vestibular/ocular reflex ≥2 best discriminated concussion from control.

Conclusion: The findings indicate that individual VOMS items and overall VOMS scores are useful in identifying concussion in collegiate athletes within 3 days of injury. Clinicians can use the cutoffs from this study to help identify concussion in collegiate athletes.
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http://dx.doi.org/10.1177/03635465211012359DOI Listing
May 2021

A randomized trial to decrease risk for diabetes among Cambodian Americans with depression: Intervention development, baseline characteristics and process outcomes.

Contemp Clin Trials 2021 May 3;106:106427. Epub 2021 May 3.

Khmer Health Advocates, USA.

Background: Depression and antidepressant medications are associated with increased risk for type 2 diabetes. It is not known if diabetes can be prevented in the setting of depression. Cambodian Americans have high rates of both depression and diabetes. This paper reports intervention development, experimental design, baseline characteristics, and process outcomes of diabetes prevention interventions for Cambodian Americans with depression, "Diabetes Risk Reduction through Eat, Walk, Sleep and Medication Therapy Management" (DREAM).

Methods: Participants were aged 35-75, Khmer speaking, at high risk for developing diabetes, and met criteria for likely depression by either a) antidepressant medication and/or b) elevated depressive symptoms at two timepoints during a study eligibility period. Treatment arms were: 1) community health educator (CHE) delivered lifestyle intervention called Eat, Walk, Sleep (EWS), 2) EWS plus pharmacist/CHE-delivered medication therapy management (EWS + MTM), and, 3) social services (SS; control).

Results: 188 participants were randomized. Treatment fidelity was high (98% checklist adherence) and on a scale from 0 to 3, participants reported high EWS treatment satisfaction (M = 2.9, SD = 0.2), group cohesion (M = 2.9, SD = 0.3), and therapeutic alliance to CHEs (M = 2.9, SD = 0.2) and to pharmacists (2.9, SD = 0.3). Attendance was challenging but highly successful; in EWS, 99% attended ≥ one session and 86% completed ≥ 24 sessions, M = 27.3 (SD = 3.7) sessions. Of those randomized to EWS + MTM, 98% attended at least one MTM session and 77%) completed ≥ 4 sessions. Retention was high, 95% at 12-month and 96% at 15-month assessments.

Conclusions: The interventions were successfully implemented. Lessons learned and suggestions for future trials are offered. ClinicalTrials.gov identifier: NCT02502929.
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http://dx.doi.org/10.1016/j.cct.2021.106427DOI Listing
May 2021

An exploration of assembly strategies and quality metrics on the accuracy of the rewarewa (Knightia excelsa) genome.

Mol Ecol Resour 2021 May 6. Epub 2021 May 6.

Genomics Aotearoa.

We used long read sequencing data generated from Knightia excelsa, a nectar producing Proteaceae tree endemic to Aotearoa (New Zealand), to explore how sequencing data type, volume and workflows can impact final assembly accuracy and chromosome reconstruction. Establishing a high-quality genome for this species has specific cultural importance to Māori and commercial importance to honey producers in Aotearoa. Assemblies were produced by five long read assemblers using data subsampled based on read lengths, two polishing strategies, and two Hi-C mapping methods. Our results from subsampling the data by read length showed that each assembler tested performed differently depending on the coverage and the read length of the data. Subsampling highlighted that input data with longer read lengths but perhaps lower coverage constructed more contiguous, kmer and gene complete than short read length input data with higher coverage. The final genome assembly was constructed into 14 pseudo-chromosomes using an initial FLYE long read assembly, a Racon/Medaka/Pilon combined polishing strategy, SALSA2 and AllHiC scaffolding, Juicebox curation, and Macadamia linkage map validation. We highlighted the importance of developing assembly workflows based on the volume and read length of sequencing data and established a robust set quality metrics for generating high quality assemblies. Scaffolding analyses highlighted that problems found in the initial assemblies could not be resolved accurately by Hi-C data and that assembly scaffolding was more successful when the underlying contig assembly was of higher accuracy. These findings provide an insight into how quality assessment tools can be implemented throughout genome assembly pipelines to inform the de novo reconstruction of a high quality genome assembly for non-model organisms.
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http://dx.doi.org/10.1111/1755-0998.13406DOI Listing
May 2021

Healthcare professionals' values about and experience with facilitating end-of-life care in the adult intensive care unit.

Intensive Crit Care Nurs 2021 Apr 19:103057. Epub 2021 Apr 19.

Faculty of Medicine and Health, University of Sydney, Camperdown, NSW, Australia. Electronic address:

Objectives: To evaluate values and experience with facilitating end-of-life care among intensive care professionals (registered nurses, medical practitioners and social workers) to determine perceived education and support needs.

Research Design: Using a cross-sectional study design, 96 professionals completed a survey on knowledge, preparedness, patient and family preferences, organisational culture, resources, palliative values, emotional support, and care planning in providing end-of-life care.

Setting: General adult intensive care unit at a tertiary referral hospital.

Results: Compared to registered nurses, medical practitioners reported lower emotional and instrumental support after a death, including colleagues asking if OK (p = 0.02), lower availability of counselling services (p = 0.01), perceived insufficient time to spend with families (p = 0.01), less in-service education for end-of-life topics (p = 0.002) and symptom management (p = 0.02). Registered nurses reported lower scores related to knowing what to say to the family in end-of-life care scenarios (p = 0.01).

Conclusion: Findings inform strategies for practice development to prepare and support healthcare professionals to provide end-of-life care in the intensive care setting. Professionals reporting similar palliative care values and inclusion of patient and family preferences in care planning is an important foundation for planning interprofessional education and support with opportunities for professionals to share experiences and strengths.
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http://dx.doi.org/10.1016/j.iccn.2021.103057DOI Listing
April 2021

Divergent Gene Expression Following Duplication of Meiotic Genes in the Stick Insect Clitarchus hookeri.

Genome Biol Evol 2021 May;13(5)

School of Biological Sciences, The University of Auckland, New Zealand.

Some animal groups, such as stick insects (Phasmatodea), have repeatedly evolved alternative reproductive strategies, including parthenogenesis. Genomic studies have found modification of the genes underlying meiosis exists in some of these animals. Here we examine the evolution of copy number, evolutionary rate, and gene expression in candidate meiotic genes of the New Zealand geographic parthenogenetic stick insect Clitarchus hookeri. We characterized 101 genes from a de novo transcriptome assembly from female and male gonads that have homology with meiotic genes from other arthropods. For each gene we determined copy number, the pattern of gene duplication relative to other arthropod orthologs, and the potential for meiosis-specific expression. There are five genes duplicated in C. hookeri, including one also duplicated in the stick insect Timema cristinae, that are not or are uncommonly duplicated in other arthropods. These included two sister chromatid cohesion associated genes (SA2 and SCC2), a recombination gene (HOP1), an RNA-silencing gene (AGO2) and a cell-cycle regulation gene (WEE1). Interestingly, WEE1 and SA2 are also duplicated in the cyclical parthenogenetic aphid Acyrthosiphon pisum and Daphnia duplex, respectively, indicating possible roles in the evolution of reproductive mode. Three of these genes (SA2, SCC2, and WEE1) have one copy displaying gonad-specific expression. All genes, with the exception of WEE1, have significantly different nonsynonymous/synonymous ratios between the gene duplicates, indicative of a shift in evolutionary constraints following duplication. These results suggest that stick insects may have evolved genes with novel functions in gamete production by gene duplication.
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http://dx.doi.org/10.1093/gbe/evab060DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8155549PMC
May 2021

Persistent Visual and Vestibular Impairments for Postural Control Following Concussion: A Cross-Sectional Study in University Students.

Sports Med 2021 Apr 21. Epub 2021 Apr 21.

Department of Kinesiology & Applied Physiology and Interdisciplinary Biomechanics and Movement Science Program, University of Delaware, Newark, DE, 19713, USA.

Objective: To examine how concussion may impair sensory processing for control of upright stance.

Methods: Participants were recruited from a single university into 3 groups: 13 participants (8 women, 21 ± 3 years) between 2 weeks and 6 months post-injury who initiated a return-to-play progression (under physician management) by the time of testing (recent concussion group), 12 participants (7 women, 21 ± 1 years) with a history of concussion (concussion history group, > 1 year post-injury), and 26 participants (8 women, 22 ± 3 years) with no concussion history (control group). We assessed sensory reweighting by simultaneously perturbing participants' visual, vestibular, and proprioceptive systems and computed center of mass gain relative to each modality. The visual stimulus was a sinusoidal translation of the visual scene at 0.2 Hz, the vestibular stimulus was ± 1 mA binaural monopolar galvanic vestibular stimulation (GVS) at 0.36 Hz, the proprioceptive stimulus was Achilles' tendon vibration at 0.28 Hz.

Results: The recent concussion (95% confidence interval 0.078-0.115, p = 0.001) and the concussion history (95% confidence interval 0.056-0.094, p = 0.038) groups had higher gains to the vestibular stimulus than the control group (95% confidence interval 0.040-0.066). The recent concussion (95% confidence interval 0.795-1.159, p = 0.002) and the concussion history (95% confidence interval 0.633-1.012, p = 0.018) groups had higher gains to the visual stimulus than the control group (95% confidence interval 0.494-0.752). There were no group differences in gains to the proprioceptive stimulus or in sensory reweighting.

Conclusion: Following concussion, participants responded more strongly to visual and vestibular stimuli during upright stance, suggesting they may have abnormal dependence on visual and vestibular feedback. These findings may indicate an area for targeted rehabilitation interventions.
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http://dx.doi.org/10.1007/s40279-021-01472-3DOI Listing
April 2021

Social disconnection and metabolic syndrome score among Cambodian Americans with depression.

Diabetes Res Clin Pract 2021 Apr 16;175:108792. Epub 2021 Apr 16.

Behavioral Sciences and Community Health, UConn Health, Farmington, CT, USA. Electronic address:

Aims: Migrants experience social disconnection and also have high risk for metabolic syndrome (MetS). This study explored associations of social alienation, social isolation, and social support with MetS among Cambodian Americans.

Methods: We conducted secondary data analysis on baseline assessments from a diabetes prevention trial for Cambodian Americans with depression and high risk for diabetes. Participants were aged 35-75, Cambodian or Cambodian-American, Khmer speaking, lived in Cambodia during the Pol Pot regime, lived in the northeastern U.S. at the time of study, endorsed elevated risk factors for diabetes and met criteria for depression by medication for depression and/or elevated depressive symptoms. They completed surveys and provided anthropometric and blood pressure measurements and fasting blood samples.

Results: In multiple linear regressions, greater social alienation was associated with increased risk for MetS. The social alienation-MetS association was stronger in men than women. Associations were not better accounted for by crude indicators of social isolation such as marital status, living alone, and number of people in the household. Social support was not associated with MetS and did not buffer the deleterious association between social alienation and MetS.

Conclusions: Decreasing social alienation may mitigate risk for MetS among migrant populations.
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http://dx.doi.org/10.1016/j.diabres.2021.108792DOI Listing
April 2021

Prevalence of Face Mask Wearing in Northern Vermont in Response to the COVID-19 Pandemic.

Public Health Rep 2021 Jul-Aug;136(4):451-456. Epub 2021 Apr 13.

238330 Essex High School, Essex Junction, VT, USA.

Objectives: Information on the prevalence of face mask use to reduce the spread of SARS-CoV-2 is needed to model disease spread and to assess the effectiveness of policies that encourage face mask use. We sought to (1) estimate the prevalence of face mask use in northern Vermont and (2) assess the effect of age and sex on the likelihood of face mask use.

Methods: We monitored the entrances to public businesses and visually assessed age, sex, and face mask use. We collected 1004 observations during May 16-30, 2020. We calculated estimates of overall face mask use and odds ratios (ORs) for effects by age and sex.

Results: Of 1004 observations, 758 (75.5%) sampled people used a face mask. Our census-weighted estimate was 74.1%. A higher percentage of females than males wore face masks (83.8% vs 67.6%). The odds of face mask use were lower among males than among females (OR = 0.52; 95% CI, 0.37-0.73). Face mask use generally decreased with decreasing age: 91.4% among adults aged >60, 70.7% among adults aged 26-60, 74.8% among people aged 15-25, and 53.3% among people aged ≤14. The OR of an adult aged >60 wearing a face mask was 14.70 times higher, for young people aged 15-25 was 2.72 times higher, and for adults aged 26-60 was 2.99 times higher than for people aged ≤14. Females aged >60 had the highest percentage of face mask use (96.3%) and males aged ≤14 had the lowest (43.8%).

Conclusions: Educational efforts promoting the use of face masks should be targeted at males and younger age groups to limit the spread of SARS-CoV-2.
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http://dx.doi.org/10.1177/00333549211009496DOI Listing
April 2021

Clinical applications of microperimetry in RPGR-related retinitis pigmentosa: a review.

Acta Ophthalmol 2021 Mar 29. Epub 2021 Mar 29.

Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, UK.

Microperimetry, or fundus-tracked perimetry, is a precise static-automated perimetric technique to assess central retinal function. As visual acuity only deteriorates at a late disease stage in RPGR-related retinitis pigmentosa (RP), alternative markers for disease progression are of great utility. Microperimetry assessment has been of critical value as an outcome measure in a recently reported phase I/II gene therapy trial for RPGR-related RP, both in terms of detecting safety and efficacy signals. Here, we performed a review of the literature. We describe the principles of microperimetry before outlining specific parameters that may be useful as outcome measures in clinical trial settings. The current state of structure-function correlations between short-wavelength autofluorescence, optical coherence tomography and adaptive optics in RPGR-related retinitis pigmentosa are also summarized.
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http://dx.doi.org/10.1111/aos.14816DOI Listing
March 2021

Age of First Exposure to Collision Sports Does Not Affect Patient Reported Outcomes in Women and Men Community Rugby Players.

Med Sci Sports Exerc 2021 Mar 12. Epub 2021 Mar 12.

Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE Interdisciplinary Program in Biomechanics and Movement Science, University of Delaware, Newark, DE School of Health and Rehabilitation Sciences, The Ohio State University College of Medicine, Columbus, OH.

Purpose: To determine the relationship between age of first exposure (AFE) to repetitive head impacts (RHI) through contact/collision sports and patient-reported outcomes in community rugby players.

Methods: We recruited community rugby players over the age of 18 with at least 1-year of contact rugby participation to complete an online survey. Participants completed the Brief-Symptoms Inventory 18 (BSI-18), Short Form Health Survey 12 (SF-12), and Satisfaction with Life Survey (SWLS) via Qualtrics. We used generalized linear models to examine the association between AFE (continuous) and patient-reported outcomes by sex, while controlling for cumulative years contact/collision sport history, age, and concussion history (yes/no). Additionally, we used Mann-Whitney U tests to compare patient-reported outcomes between AFE <12 and AFE >12.

Results: 1,037 rugby players [31.6 + 11.3 years (range: 18-74), 59.1% men] participated in this study. Whether analyzed continuously or dichotomously at age 12, younger AFE was not associated with worse patient-reported outcomes for either men or women. Positive concussion history was a significant predictor of worse BSI-18 sub-scores, SF-12 sub-scores, and SWLS in women and worse BSI-18 sub-scores in men. Cumulative contact/collision sport history was a significant predictor of better BSI-18 Depression and SF-12 (Mental Component Summary, MCS) sub-scores in men only. In men and women, older age was a significant predictor of better BSI-18 Depression, Anxiety, and GSI sub-scores, better SWLS (in men only), and better SF-12 MCS, but worse SF-12 (Physical Component Summary).

Conclusion: Younger AFE to contact/collision sport is not associated with worse patient-reported outcomes in early adult rugby players. Concussion history was predictive of worse patient-reported outcomes.
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http://dx.doi.org/10.1249/MSS.0000000000002657DOI Listing
March 2021

24 h-Heart Rate Variability as a Communication Tool for a Personalized Psychosomatic Consultation in Occupational Health.

Front Neurosci 2021 11;15:600865. Epub 2021 Feb 11.

Clinic for Psychosomatic Medicine and Psychotherapy, University Hospital Ulm, Ulm, Germany.

New tools for non-specific primary prevention strategies covering somatic and mental health in occupational medicine are urgently needed. Heart rate variability (HRV) reflects the capacity of the body to adapt to environmental challenges and of the mind to regulate emotions. Hence, a 24 h-measurement of HRV offers a unique possibility to quantify the interaction between situation-specific emotional regulation within a specific psychosocial environment and physiological state, thereby increasing self-perception and inducing motivation to change behavior. The focus of the present study represents such a 24 h-measurement of HRV and its presentation as a comprehensive graph including protocol situations of the client. A special training program for occupational health physicians and questionnaires for clients were developed and administered. The article reports the first data of the study "", an investigator-initiated, interventional, single-arm, open (non-blinded), multicenter, national trial with 168 participants. They reported a significantly improved perception of their bodily needs after the consultation (from Median = 7, interquartile range 5-8 to Median = 8, interquartile range 7-9; scale range from 1 to 10; < 0.001, Wilcoxon rank test; effect size 0.49). The 16 occupational health physicians stated that the measurement of HRV was very well suited to enter into dialog with the managers and was feasible to show interactions between situations, thoughts, feelings, and bodily reactions. Taken together, we show that a 24 h-HRV-measurement can be a feasible and effective approach for holistic, psychosomatic primary prevention in occupational medicine. We discuss possible mechanisms for improving the individual health via the consultation, containing mindset and improved ANS activity.
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http://dx.doi.org/10.3389/fnins.2021.600865DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7905098PMC
February 2021

Chronic untreated retinal detachment in a patient with choroideremia provides insight into the disease process and potential therapy.

Eur J Ophthalmol 2021 Feb 11:1120672121994722. Epub 2021 Feb 11.

Oxford University Hospitals NHS Foundation Trust, Oxford, UK.

Aim: We present the case of a 72-year-old male with advanced choroideremia and a left chronic rhegmatogenous retinal detachment, which to our knowledge is the first formal report of a retinal detachment in this disease.

Background: Choroideremia is a rare X-linked inherited retinal dystrophy, caused by mutations in the gene which encodes Rab escort protein 1 (REP1), and affected males typically experience a progressive centripetal loss of vision. The disease pathology is caused by a primary retinal pigment epithelium degeneration, which leads to secondary loss of photoreceptors and choriocapillaris. This in turn leads to fusion of the degenerate outer retinal layers resulting in a retinopexy that is known to make subretinal gene therapy particularly challenging in these patients.

Conclusion: Although retinal gene therapy is commonly targeted to the macular area in choroideremia, the observation of a rhegmatogenous retinal detachment indicates that the peripheral retina may not fuse with the residual choroid as occurs in the equatorial and macular regions. If this hypothesis is correct, targeting gene therapy to the retinal periphery even in advanced cases may be feasible and could potentially be used to preserve navigational vision.
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http://dx.doi.org/10.1177/1120672121994722DOI Listing
February 2021

Variants in PCSK7, PNPLA3 and TM6SF2 are risk factors for the development of cirrhosis in hereditary haemochromatosis.

Aliment Pharmacol Ther 2021 04 10;53(7):830-843. Epub 2021 Feb 10.

London, UK.

Background: Cirrhosis develops in <10% of individuals homozygous for the C282Y variant in the homeostatic iron regulator (HFE) gene. Carriage of PCSK7:rs236918 is associated with an increased risk of cirrhosis in this population.

Aim: To determine if genetic variants significantly associated with the risk of alcohol- and NAFLD-related cirrhosis also modulate the cirrhosis risk in C282Y homozygotes.

Methods: Variants in PCSK7, PNPLA3, TM6SF2, MBOAT7 and HSD17B13 were genotyped in 1319 C282Y homozygotes, from six European countries, of whom 171 (13.0%) had cirrhosis. Genotypic and allelic associations with the risk for developing cirrhosis were assessed, adjusting for age and sex. Fixed effects meta-analyses of the adjusted summary data for each country were performed. Post hoc association testing was undertaken in the 131 (76.6%) cases and 299 (26.0%) controls with available liver histology.

Results: Significant associations were observed between PCSK7:rs236918 (OR = 1.52 [95% CI 1.06-2.19]; P = 0.022; I  = 0%); PNPLA3:rs738409 (OR = 1.60 [95% CI 1.22-2.11]; P = 7.37 × 10 ; I  = 45.5%) and TM6SF2:rs58542926 (OR = 1.94 [95% CI 1.28-2.95]; P = 1.86 × 10 ; I  = 0%) and the cirrhosis risk in C282Y homozygotes. These findings remained significant in the subpopulation with available liver histology. The population-attributable fractions were 5.6% for PCSK7:rs236918, 13.8% for PNPLA3:rs738409, 6.5% for TM6SF2:rs58542926 and 24.0% for carriage of all three variants combined.

Conclusions: The risk of cirrhosis associated with carriage of PCSK7:rs236918 was confirmed in this much larger population of C282Y homozygotes. In addition, PNPLA3:rs738409 and TM6SF2:rs58542926 were established as significant additional risk factors. More detailed genetic testing of C282Y homozygotes would allow risk stratification and help guide future management.
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http://dx.doi.org/10.1111/apt.16252DOI Listing
April 2021

The unique challenge of the nurse-patient in the intensive care.

Authors:
Thomas Buckley

Aust Crit Care 2021 01;34(1):1-2

Susan Wakil School of Nursing and Midwifery, Faculty of Medicine and Health, University of Sydney, Building MO2, NSW 2065, Australia. Electronic address:

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http://dx.doi.org/10.1016/j.aucc.2020.12.006DOI Listing
January 2021

Optimal carbon partitioning helps reconcile the apparent divergence between optimal and observed canopy profiles of photosynthetic capacity.

Authors:
Thomas N Buckley

New Phytol 2021 06 8;230(6):2246-2260. Epub 2021 Mar 8.

Department of Plant Sciences, University of California, Davis, One Shields Ave, Davis, CA, 95616, USA.

Photosynthetic capacity per unit irradiance is greater, and the marginal carbon revenue of water (∂A/∂E) is smaller, in shaded leaves than sunlit leaves, apparently contradicting optimization theory. I tested the hypothesis that these patterns arise from optimal carbon partitioning subject to biophysical constraints on leaf water potential. In a whole plant model with two canopy modules, I adjusted carbon partitioning, nitrogen partitioning and leaf water potential to maximize carbon profit or canopy photosynthesis, and recorded how gas exchange parameters compared between shaded and sunlit modules in the optimum. The model predicted that photosynthetic capacity per unit irradiance should be larger, and ∂A/∂E smaller, in shaded modules compared to sunlit modules. This was attributable partly to radiation-driven differences in evaporative demand, and partly to differences in hydraulic conductance arising from the need to balance marginal returns on stem carbon investment between modules. The model verified, however, that invariance in the marginal carbon revenue of N (∂A/∂N) is in fact optimal. The Cowan-Farquhar optimality solution (invariance of ∂A/∂E) does not apply to spatial variation within a canopy. The resulting variation in carbon-water economy explains differences in capacity per unit irradiance, reconciling optimization theory with observations.
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http://dx.doi.org/10.1111/nph.17199DOI Listing
June 2021

Concussion research: Moving beyond the natural history.

Authors:
Thomas A Buckley

J Sport Health Sci 2021 Mar 14;10(2):111-112. Epub 2021 Jan 14.

Kinesiology and Applied Physiology, University of Delaware, Newark, DE 19713, USA. Electronic address:

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http://dx.doi.org/10.1016/j.jshs.2021.01.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7987566PMC
March 2021

Detailed description of Division I ice hockey concussions: Findings from the NCAA and Department of Defense CARE Consortium.

J Sport Health Sci 2021 Mar 14;10(2):162-171. Epub 2021 Jan 14.

Kinesiology and Applied Physiology, University of Delaware, Newark, DE 19713, USA.

Objective: Since concussion is the most common injury in ice hockey, the objective of the current study was to elucidate risk factors, specific mechanisms, and clinical presentations of concussion in men's and women's ice hockey.

Methods: Ice hockey players from 5 institutions participating in the Concussion Assessment, Research, and Education Consortium were eligible for the current study. Participants who sustained a concussion outside of this sport were excluded. There were 332 (250 males, 82 females) athletes who participated in ice hockey, and 47 (36 males, 11 females) who sustained a concussion.

Results: Previous concussion (odds ratio (OR) = 2.00; 95% confidence interval (95% CI): 1.02‒3.91) was associated with increased incident concussion odds, while wearing a mouthguard was protective against incident concussion (OR = 0.43; 95%CI: 0.22‒0.85). Overall, concussion mechanisms did not significantly differ between sexes. There were specific differences in how concussions presented clinically across male and female ice hockey players, however. Females (9.09%) were less likely than males (41.67%) to have a delayed symptom onset (p = 0.045). Additionally, females took significantly longer to reach asymptomatic (p = 0.015) and return-to-play clearance (p = 0.005). Within the first 2 weeks post-concussion, 86.11% of males reached asymptomatic, while only 45.50% of females reached the same phase of recovery. Most males (91.67%) were cleared for return to play within 3 weeks of their concussion, compared to less than half (45.50%) of females.

Conclusion: The current study proposes possible risk factors, mechanisms, and clinical profiles to be validated in future concussions studies with larger female sample sizes. Understanding specific risk factors, concussion mechanisms, and clinical profiles of concussion in collegiate ice hockey may generate ideas for future concussion prevention or intervention studies.
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http://dx.doi.org/10.1016/j.jshs.2021.01.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7987562PMC
March 2021

Factors Associated with Symptom Reporting in U.S. Service Academy Cadets and NCAA Student Athletes without Concussion: Findings from the CARE Consortium.

Sports Med 2021 May 11;51(5):1087-1105. Epub 2021 Jan 11.

University of Delaware, Newark, DE, USA.

Background: Symptom resolution is a key marker in determining fitness for return to activity following concussion, but in some cases, distinguishing persistent symptoms due to concussion versus symptoms related to other factors can be challenging.

Objective: To determine base rates of postconcussional syndrome (PCS) diagnostic categorization in healthy cadets and student athletes with no recent concussion.

Methods: 13,009 cadets and 21,006 student athletes completed baseline preseason testing. After inclusion/exclusion criteria were applied, the final sample included 12,039 cadets [9123 men (75.8%); 2916 women (24.2%)] and 18,548 student athletes [10,192 men (54.9%); 8356 women (45.1%)]. Participants completed the Sport Concussion Assessment Tool-3rd Edition (SCAT3) symptom evaluation as part of baseline preseason testing. The PCS diagnostic categorization was classified by the International Classification of Diseases, 10th Revision (ICD-10) symptom criteria for PCS.

Results: In the absence of recent concussion, subgroups of cadets (17.8% of men; 27.6% of women) and student athletes (11.4% of men; 20.0% of women) reported a cluster of symptoms that would meet the ICD-10 symptom criteria for PCS. Participants with insufficient sleep and/or preexisting conditions (e.g., mental health problems), freshmen cadets, and cadets at the U.S. Coast Guard Academy and at the U.S. Air Force Academy (freshmen were tested during basic cadet training) were more likely to report a cluster of symptoms that would meet the ICD-10 symptom criteria for PCS.

Conclusion: The ICD-10 symptom criteria for PCS can be mimicked by preexisting conditions, insufficient sleep, and/or stress. Findings support person-specific assessment and management of symptoms following concussion.
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http://dx.doi.org/10.1007/s40279-020-01415-4DOI Listing
May 2021

Low luminance visual acuity as a clinical measure and clinical trial outcome measure: a scoping review.

Ophthalmic Physiol Opt 2021 Mar 6;41(2):213-223. Epub 2021 Jan 6.

Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.

Purpose: The measurement of standard visual acuity (VA) is the most well-known part of any ophthalmic examination to indicate visual function. Despite this, it is insensitive in detecting early disease changes. Therefore, other visual function tests have been developed including low luminance VA (LLVA) and low luminance deficit (LLD). This scoping literature review aims to summarise the current published applications of LLVA and LLD assessments to evaluate their utility as clinical markers and research outcome measures in a variety of ophthalmic conditions.

Recent Findings: Sixty-five peer-reviewed publications were included. LLVA was pioneered for use in geographic atrophy, a subtype of age-related macular degeneration, which remains the mainstay of its clinical application. However, other studies have reported additional useful applications in inherited retinal diseases including rare maculopathies and rod-cone dystrophies. Although there are some variations in testing methodology, use of the standard Early Treatment Diabetic Retinopathy Study (ETDRS) chart with a 2.0 log unit neutral density filter is the most popular approach. The optimal testing luminance is still to be defined.

Summary: Overall, LLVA is an earlier clinical marker of change in central retinal function than standard VA. It has been shown to be a risk factor for disease progression and a better indicator of a patient's level of everyday visual function. It is inexpensive and simple to implement using readily available standard ophthalmic equipment.
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http://dx.doi.org/10.1111/opo.12775DOI Listing
March 2021

A Cluster of Corneal Donor Rim Cultures Positive for Achromobacter Species Associated With Contaminated Eye Solution.

Cornea 2021 Feb;40(2):223-227

Department of Ophthalmology, Massachusetts Eye and Ear, Harvard Medical School, Boston, MA. Dr. André is now with Centre International de Recherche en Infectiologie (CIRI), Inserm U1111, Université́ Claude Bernard Lyon 1, CNRS UMR5308, Ecole Normale Supérieure de Lyon, Lyon, France.

Purpose: To investigate a cluster of corneoscleral rim cultures positive for Achromobacter species over a 6-month period at Massachusetts Eye and Ear.

Methods: An increased rate of positive corneal donor rim cultures was noted at Massachusetts Eye and Ear between July and December 2017. Positive cultures were subjected to identification and antimicrobial susceptibility testing by phenotypic (MicroScan WalkAway) and genotypic (16S rDNA sequencing) methods. Samples of the eye wash solution (GeriCare) used in the eye bank were also evaluated. Antimicrobial activity of Optical-GS against Achromobacter spp. at 4°C and 37°C was assessed by time-kill kinetics assay.

Results: Of 99 donor rims cultured, 14 (14.1%) grew bacteria with 11 (78.6%) due to uncommon nonfermenting Gram-negative bacilli. These had been identified by standard automated methods as Achromobacter (n = 3), Alcaligenes (n = 3), Ralstonia (n = 2), Pseudomonas (n = 2), and Stenotrophomonas (n = 1). Eight of these 11 isolates were subsequently available for molecular identification, and all were identified as Achromobacter spp. Six bottles of eyewash solution were evaluated and were positive for abundant Achromobacter spp. (3.4 × 105 ± 1.1 CFU/mL). Optisol-GS had no bactericidal activity against Achromobacter spp. at 4°C after 24-hour incubation but was bactericidal at 37°C. None of the patients who had received the contaminated corneas developed postoperative infection.

Conclusions: An eyewash solution arising from a single lot was implicated in the contamination of donor rims by Achromobacter spp. The isolates were able to survive in the Optisol-GS medium at the recommended storage temperature. This highlights the need to continue improving protocols for tissue preparation and storage.
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http://dx.doi.org/10.1097/ICO.0000000000002473DOI Listing
February 2021

Clinical Reaction Time After Concussion: Change From Baseline Versus Normative-Based Cutoff Scores.

J Athl Train 2020 Dec 22. Epub 2020 Dec 22.

University of Delaware, Newark.

Context: Pre-season testing is often used to establish baseline scores for post-concussion interpretation. However, pre-season testing can be time-intensive and cost-prohibitive, in which case normative data may be used for post-injury interpretation.

Objective: To compare change from baseline and normative-based cutoff scores in interpreting clinical reaction time (RTclin) following concussion.

Design: Prospective case-control study.

Setting: Multi-site study with testing completed in university athletic training rooms.

Patients Or Other Participants: An overlapping sample of 99 participants (age=19.0±1.1 years) evaluated within 6 hours post injury, 176 participants (age 18.9±1.1 years) evaluated 24-48 hours post injury, and 214 participants (18.9±1.1 years) evaluated at the time they were cleared to begin a return-to-play progression. Concussion participants were compared to 942 control participants (age=19.0±1.0 years) who did not sustain a concussion during the study period but completed preseason baseline testing one year apart.

Main Outcome Measures: At each time point, follow-up RTclin (i.e., post injury or year 2) was compared to individualized year 1 preseason baseline RTclin and to normative baseline data (i.e., sex- and sport-specific). Receiver operating characteristic curves were used to compare sensitivity and specificity of RTclin change from baseline and normative-based cutoff scores.

Results: Within 6h, change from baseline of 16ms maximized combined sensitivity (52%) and specificity (78%, AUC=0.702), while normative-based cutoff scores of 19ms maximized combined sensitivity (45%) and specificity (86%, AUC=0.700). At 24-48h, change from baseline of 2ms maximized combined sensitivity (64%) and specificity (61%, AUC=0.666), while normative-based cutoff scores of 0ms maximized combined sensitivity (63%) and specificity (62%, AUC=0.647).

Conclusions: Normative-based cutoff scores can be used for interpreting RTclin scores following concussion when individualized baseline data is not available, although low sensitivity and specificity may limit clinical use as a stand-alone test.
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http://dx.doi.org/10.4085/JAT0457-20DOI Listing
December 2020

Coordinated decline of leaf hydraulic and stomatal conductances under drought is not linked to leaf xylem embolism for different grapevine cultivars.

J Exp Bot 2020 12;71(22):7286-7300

Department of Viticulture and Enology, University of California, Davis, 595 Hilgard Lane, Davis, CA, USA.

Drought decreases water transport capacity of leaves and limits gas exchange, which involves reduced leaf leaf hydraulic conductance (Kleaf) in both the xylem and outside-xylem pathways. Some literature suggests that grapevines are hyper-susceptible to drought-induced xylem embolism. We combined Kleaf and gas exchange measurements, micro-computed tomography of intact leaves, and spatially explicit modeling of the outside-xylem pathways to evaluate the role of vein embolism and Kleaf in the responses of two different grapevine cultivars to drought. Cabernet Sauvignon and Chardonnay exhibited similar vulnerabilities of Kleaf and gs to dehydration, decreasing substantially prior to leaf xylem embolism. Kleaf and gs decreased by 80% for both cultivars by Ψ leaf approximately -0.7 MPa and -1.2 MPa, respectively, while leaf xylem embolism initiated around Ψ leaf = -1.25 MPa in the midribs and little to no embolism was detected in minor veins even under severe dehydration for both cultivars. Modeling results indicated that reduced membrane permeability associated with a Casparian-like band in the leaf vein bundle sheath would explain declines in Kleaf of both cultivars. We conclude that during moderate water stress, changes in the outside-xylem pathways, rather than xylem embolism, are responsible for reduced Kleaf and gs. Understanding this mechanism could help to ensure adequate carbon capture and crop performance under drought.
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http://dx.doi.org/10.1093/jxb/eraa392DOI Listing
December 2020

Diagnosed concussion is associated with increased risk for lower extremity injury in community rugby players.

J Sci Med Sport 2021 Apr 28;24(4):368-372. Epub 2020 Oct 28.

Department of Kinesiology and Applied Physiology, University of Delaware, USA; Interdisciplinary Program in Biomechanics and Movement Science, University of Delaware, USA. Electronic address:

Objectives: To determine (1) the association between lifetime diagnosed concussion and lower extremity musculoskeletal injury (LE-MSI) among community rugby union players and (2) the sex specific risk of LE-MSI given concussion history among males and females.

Design: Retrospective survey.

Methods: 1037 (59.0% male, (612/1037), age: 31.6 ± 11.3 years) rugby players (10.1 ± 8.1 years played) completed an online survey to ascertain injury history. A chi-squared test of association was performed between concussion and LE-MSI; significant outcomes were followed-up with an odds ratio. A binary logistic regression with any LE-MSI (yes/no) as the outcome and concussion (yes/no) and sex (male/female) as predictors was performed to determine if there was a sex by concussion interaction.

Results: There was an overall significant association between concussion and any LE-MSI(χ(1) = 13.055, p < 0.001, OR = 2.30 [95%CI: 1.45, 3.65]). Both male (OR = 2.21) and females (OR = 2.49) had significant associations for concussion and LE-MSI, but there were no differences between sex for risk of LE-MSI (R = 0.024, p = 0.999).

Conclusions: Community rugby players with a history of concussion are >2× more likely to also experience an LE-MSI than those without a history of concussion. There were no differences in the odds of LE-MSI between males and females with a history of diagnosed concussion. In line with current World Rugby injury prevention programs, future research should aim to reduce LE-MSI incidence to maximize player safety and wellness through targeted injury prevention and teams should utilize a conservative return to play protocols following concussion.
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http://dx.doi.org/10.1016/j.jsams.2020.10.013DOI Listing
April 2021

Inner retinal thickening affects microperimetry thresholds in the presence of photoreceptor thinning in patients with retinitis pigmentosa.

Br J Ophthalmol 2020 Oct 30. Epub 2020 Oct 30.

Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.

Background: Loss of photoreceptors cause degeneration in areas of the retina beyond the photoreceptors. The pattern of changes has implications for disease monitoring and measurement of functional changes. The aim of the study was to study the changes in inner retinal structure associated with photoreceptor disease, and the impact of these on microperimetry threshold.

Methods: This retrospective cohort study was conducted on optical coherence tomography (OCT) images and microperimetry tests collected between 2013 and 2019. 22 eyes with retinitis pigmentosa completed both OCT imaging and microperimetry assessment. 18 control eyes underwent OCT imaging. Photoreceptor layer and inner retinal thickness calculated for different eccentric areas were obtained. The relationship between the photoreceptor layer and inner retinal thickness, and microperimetry threshold was explored.

Results: Central 1° photoreceptor layer and inner retinal thickness were 96±34 and 139±75 μm in patients, and 139±15 and 62±14 μm in controls. Photoreceptor layer thickness differed between patient and control groups across increasing visual field areas (p<0.01, Kruskal-Wallis 1-way ANOVA), whereas the inner retinal thickness significantly differed between groups for the central 1° and 3° only. Microperimetry thresholds were explained by a combination of photoreceptor thickness (coefficient 0.15, 95% CI 0.13 to 0.18) and inner retinal thickness (coefficient 0.05, 95% CI 0.03 to 0.06).

Conclusion: OCT shows evidence of remodelling in the inner retinal layers secondary to photoreceptor disease. This appears to have an impact on microperimetry threshold measurements.
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http://dx.doi.org/10.1136/bjophthalmol-2020-317692DOI Listing
October 2020

Gait Performance Is Associated with Subsequent Lower Extremity Injury following Concussion.

Med Sci Sports Exerc 2020 11;52(11):2279-2285

Purpose: The purpose was to examine gait characteristics between collegiate athletes who did and did not sustain a lower-extremity musculoskeletal (LEMSK) injury in the year after concussion.

Methods: Thirty-four NCAA collegiate athletes with diagnosed concussions were divided into two groups based on if they did (n = 16) or did not (n = 18) sustain a LEMSK in the year after concussion. Participants completed baseline testing before the start of the season and again at return to play postconcussion. Injuries were tracked using an electronic medical database. Participants were instrumented with three APDM Opal triaxial accelerometers and performed five single-task (ST) and five dual-task (DT) gait trials. Participants traversed a 10-meter walkway, turned around a specified endpoint, and returned to the original line. During DT, participants simultaneously walked and answered mini-mental style questions. A linear mixed-effects model assessed interactions and/or main effects between groups for gait speed, double support time, cadence, stride length, and cognitive accuracy.

Results: The LEMSK group walked slower (ST, 1.15 ± 0.10 m·s; DT, 1.01 ± 0.10 m·s) than the uninjured group (ST, 1.23 ± 0.11 m·s; DT, 1.10 ± 0.11 m·s) during both ST (P = 0.04) and DT (P = 0.03). The injury group spent longer in double support (ST, 20.19% ± 2.34%; DT, 21.92% ± 2.13%) than the uninjured group (ST, 18.16% ± 2.60%; DT, 20.00% ± 2.32%) during both ST (P = 0.02) and DT (P = 0.02). The injury group had a significantly lower cognitive accuracy (89.56% ± 6.48%) than the uninjured group (95.40% ± 7.08%) across time points (P = 0.02).

Conclusions: There were significant differences in gait characteristics and cognitive accuracy between those who did and did not sustain a LEMSK injury after concussion. The LEMSK group demonstrated a conservative gait strategy both before and after their concussive injury.
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http://dx.doi.org/10.1249/MSS.0000000000002385DOI Listing
November 2020