Pseudomonas aeruginosa strains could be influenced by differences in antibiotic resistance and virulence. At the present time, it is unclear which type of immune responses enables uncontrolled invasion of opportunistic pathogens. The conditional pathogenicity of Pseudomonas aeruginosa served as an inspiration to begin a study on this bacterium. The aim of this study was to gain insight into selected parameters describing immune responses with regards to the adaptable agents of this pathogen. For the analysis of the specific immune response, the potential of Pseudomonas aeruginosa to stimulate lymphocytes, including Th17 lymphocytes, dendritic cells and other components of the adaptive immune response, was examined. The highest percentage of CD83+CD1a-HLA-DR++ cells was found after stimulation with lysates of strains isolated from the patients with severe systemic infection. We found statistically significant differences in percentages of HLA-DR+ PBMCs and MFI of HLA-DR between groups of Pseudomonas aeruginosa strains isolated from the patients with different clinical courses of infection. Our results suggest that the clinical course and outcomes of Pseudomonas aeruginosa infections are not associated with impairment of the specific immune response.The immune response to  Pseudomonas aeruginosa. Pseudomonas aeruginosa is commonly recognized as an opportunistic pathogen and is not pathogenic in healthy populations [Pseudomonas aeruginosa is also a very important epidemiological problem of nosocomial infections characterized by a treatment-resistant course, including pneumonia, and including those associated with the use of artificial ventilation, intra-abdominal infections after surgery, burn wounds, meningeal infections and sepsis. This bacterium is the main epidemiological factor of chronic pneumonia in people with cystic fibrosis (CF), and the long-term immune response of these patients to the presence of Pseudomonas aeruginosa causes the final destruction of the lungs by inflammatory factors, tragically closing the pathogen–host vicious cycle [Pseudomonas aeruginosa is its high virulence-modifying and immune-bypassing ability, so it is interesting to gain additional insight into how Pseudomonas aeruginosa affects host defense mechanisms. The conditional nature of Pseudomonas aeruginosa pathogenicity was the inspiration to begin researching this bacterium. It is not clear at this time which changes in the immune system allow opportunistic pathogens to proliferate and initiate a clinically apparent invasion. This study attempts to understand differences which could be associated with the invasive course of Pseudomonas aeruginosa infections and to answer the question as to what extent selected elements of specific immune responses are influenced by different adaptation factors of this pathogen, e.g., antibiotic resistance, type of colony growth or genetic regulation of virulence. We chose to analyze the reactivity of well-functioning immune system components against Pseudomonas aeruginosa strains isolated from different anatomical locations that differ in antibiotic resistance and virulence phenotype. For this analysis, the potential of Pseudomonas aeruginosa for stimulation of dendritic cell maturation, HLA-DR expression, Th17 lymphocytes differentiation and release of pro- and anti-inflammatory cytokines was evaluated.The human immune system is constantly interacting with the external environment, as well as many pathogens. The nature of this interaction is dynamic—it changes over time; it also intensifies and specifies both the way in which the attacked organism fights and eliminates the pathogen, and, at the same time, pathogen virulence changes. Moreover, pathogenic bacteria are not only able to effectively oppose immune mechanisms, but, at the same time, are able to resist additional external factors, such as the antibiotics used. One important bacterium, which shows special adaptive properties, is Gram-negative ulations . Occasioulations . On the us cycle . Anotherus cycle ,5,6,7,8.Pseudomonas aeruginosa was isolated. The average age of the respondents was 60.8 ± 1.41 years. Ten patients were hospitalized in the Independent Public Clinical Hospital No. 4. in Lublin and the pathogen was isolated in the hospital lab. Based on the course of the disease, which was determined by an analysis of medical documentation obtained from the archive of SPSK4, five patients were selected in two groups:The study included 15 patients (7 women and 8 men) from whom Pseudomonas aeruginosa, which eventually resulted in patient death.Group A—5 patients with severe systemic infection with Pseudomonas aeruginosa, with successful completion (cure or remission of recurrent infections).Group B—5 patients with a urinary tract infection caused by Pseudomonas aeruginosa took place in the microbiological laboratory of Luxmed in Lublin and were included as group C—5 outpatients with asymptomatic colonization of upper respiratory tract by Pseudomonas aeruginosa.Five were outpatients, and isolation of Pseudomonas aeruginosa strains were grown in Columbia Agar supplemented with 5% Sheep Blood  and MacConkey Agar  as a homogeneous, abundant monoculture of blood culture and monoculture urine growth above 105 CFU/mL (significant bacteriuria). From nose and throat swabs, Pseudomonas aeruginosa was cultured from the throat in an average of 5–10 colonies, which indicated colonization against the dominant growth of the physiological flora. The identification of the species Pseudomonas aeruginosa was performed by using commercial APINE identification tests . The purity of the test strains was checked under a microscope (Gram-stained slide) and by analyzing the morphology of bacterial colonies grown on Columbia agar supplemented with 5% sheep blood  and MacConkey agar .The biological samples taken from patients were as follows: Group A—peripheral blood, which was collected into media of the BacT/Alert system ; Group B—urine; Group C—nose and throat swabs. The cultures of the materials were prepared in accordance with routine microbiological diagnostics. Pseudomonas aeruginosa. The healthy volunteers did not suffer from any bacterial or viral infection for at least one month prior to the date of blood collection and did not receive any medication that may affect the immune system. Volunteers also did not suffer from chronic diseases or allergies.Blood samples of healthy volunteers with a mean age of 29.9 ± 7.5 years (3 women and 7 men) were used to evaluate selected parameters of the immune response to the above strains of The study was conducted in accordance with a protocol approved by the Bioethics Committee of the Medical University of Lublin in resolution KE-0254/184/2013. Informed consent was obtained from all subjects involved in the study.Pseudomonas aeruginosa.Bacteria obtained from diagnostic laboratories were frozen at −80 °C, using the Microbank system , which enables safe freezing and reclamation of frozen cells. As the study progressed, live suspensions and their lysates were prepared from the frozen strains of 2+ and Mg2+ . A density of 1 McFarland  was measured by using a Densimat photometer  to determine the concentration of the solution by measuring the intensity of light scattering. Pure bacterial cultures were isolated on solid media plates—Columbia Agar  was prepared according to the following recipe: 400 mL agar solution with manufacturer’s recommended concentration was sterilized by autoclaving, and 20 mL of sheep blood  was added. After 24 h of culture, the bacteria were again sieved to the same medium, and after 24 h, pure culture suspensions were prepared in Dulbecco’s PBS with CaPseudomonas aeruginosa colonies on solid media, the mucoid and non-mucoid types were differentiated. Mucus type growth was observed in strains 2, 3, 5, 7, 9, 11 and 14.Based on the type of growth of Live bacterial suspensions prepared as above were rapidly frozen at −80 °C and thawed to pre-disintegrate the bacterial cells. They were subsequently sonicated in a Branson Ultrasonics 2510  sonicator at a temperature of 46 °C for 30 min. The resulting lysates were filtered through 0.22 μm Millex GP filters , separated into Eppendorf tubes of 1.5 mL and frozen at −80 °C. The whole procedure of lysates ensured the sterility of the final product.The total protein concentration in the lysates was determined with the Bradford protein assay, using the Bradford Reagent  and the SmartSpec Plus spectrophotometer  by measuring the absorbance of the samples at 595 nm. The exact protein concentration of the samples was determined by interpolation from a standard curve made by measuring the absorbance of a dilution series of bovine serum albumin (BSA)  of known concentrations within the linear response range of the Bradford protein assay.algD, lasB, toxA, plcH, plcN, exoS and nan1 genes was determined in the examined Pseudomonas aeruginosa strains. The primers sequences  are summarized in Using the polymerase chain reaction (PCR) method, the presence of the algD and nan1 genes and 100 bp for other genes. The following program was used on the iCycler Thermal Cycler : initial denaturation—94 °C for 3 min, 30 cycles: 94 °C after 30 s (denaturation), 55 °C for 1 min. , 72 °C for 1 min. Then 30 s (elongation) and one stage of final extension: 72 °C for 5 min.Then 1 kb markers  were used for Each gene was amplified separately. The previously developed procedure for detecting the presence of these genes, as described in the literature, was followed .On the basis of the presence of individual genes, 4 groups were defined in the tested material . The gro+2 or Mg+2  and then overlaid on Gradisol L  and centrifuged for 20 min, with an acceleration of 700× g. The collected PBMCs were washed twice in the same PBS for 7 min at 700× g. Then the collected cells were suspended in 3 mL of AIM V Serum Medium  and the cells were counted and their viability determined by using Trypan Blue  and a countess cell counter . It was assumed that cell viability could not be less than 90%.Peripheral blood was diluted 1:2 with PBS w/o Ca6 cells to each well and 3 mL of AIM V Serum Free Medium , and then adding one of 15 lysates  to each well. The dose of bacterial lysates was set after optimization of protocol. The cells were cultured in an incubator at 5% CO2, 37 °C and 95% humidity for 72 h.Cells were cultured in Cellstar six-well plates  by adding 2 × 10Then 0.5 mL of the suspension was removed from each well for the determination of dendritic cells, and to the remainder of the culture the same volume of lysates was added again to restore the lymphocytes and Brefeldin A  was added in the amount recommended by the manufacturer. After carefully mixing the contents, the cells were incubated for another 6 h. The addition of Brefeldin A was to block intracellular transport within the Golgi reticulum and to inhibit secretion of IL-17A into the medium by lymphocytes, as the latter procedures are based on the intracellular determination of IL-17A.g. The collected supernatants were frozen at −80 °C for determination of the pro- and anti-inflammatory cytokine profile by cytometric methods.After restimulation, the cultured cells were separated from the supernatants by centrifugation for 7 min at 700× After 72 h of PBMC stimulation with bacterial lysates, maturation of dendritic cells was evaluated with the use of flow cytometry. We excluded from analysis cultures with viability lower than 90%. Unstimulated PBMC were used as negative control, and ionomycin  stimulated cells were used as positive control. Cells were stained with FITC-labeled Mouse IgG1 κ anti-human CD83 , PE Mouse IgG1 κ anti-Human CD1a  and PE-Cy5 Mouse IgG2a κ anti-Human HLA-DR . Acquisition and analysis were carried out in the Guava EasyCyte  cytometer with InCyte software. CD83+CD1a-HLA-DR++ cells were counted as mature DCs, CD83+CD1a+HLA-DR+ as partially matured and CD83-CD1a+HLA-DR+/low as immature. We also evaluated percentages of HLA-DR+ PBMC and expression of HLA-DR on PBMC shown as mean fluorescence intensity (MFI). The representative case of gating strategy and analysis is shown in the g). Rinse operation with permeabilization buffer was repeated. In the next step, 100 μL permeabilization buffer and 10 μL Mouse IgG1κ anti-human-IL-17A-PE  were added to the tubes and incubated for 20 min in the dark at room temperature. After this time, it was rinsed with permeabilization buffer and centrifuged . The resulting cells were suspended in 1 mL Flow Cytometry Staining Buffer . Acquisition and analysis were carried out in the Guava EasyCyte  cytometer and InCyte software. Unstimulated and incubated with Brefeldin A cells were used as negative control; PBMC stimulated with ionomycin and incubated with Brefeldin A served as positive control. We excluded from analysis cultures with viability lower than 90%. The representative case of gating strategy and analysis is shown in the Cells from culture, after restimulation with bacterial lysates and incubation with Brefeldin A, were washed and incubated with PE-Cy5 Mouse IgG2a κ Anti-Human CD3  and FITC Mouse BALB/c IgG1 anti-human CD4  in the dark at room temperature for 20 min. After incubation, 100 μL IC Fixation Buffer  was added and incubated for another 20 min, and then 2 mL permeabilization buffer  was added and centrifuged , using a commercial BD CBA Human Inflammatory Cytokines Kit  according to the procedure specified by the manufacturer. The study was performed on a BD FACSCalibur dual-laser flow cytometer , using CellQuest Pro data acquisition and analysis software . We analyzed concentrations of IL-1β, IL-6, IL-8, IL-10 and TNF. Measurements of IL-12 level determinations were excluded from further analysis, as the obtained results were below the detection level in all tested samples.p ≤ 0.05.Statistical analysis of the results was carried out by using the Statistica 10 PL software . Results are presented as median, interquartile range (IQR) and minimal and maximal values. Because the variables had no normal distribution, as evidenced by the Shapiro–Wilk test, non-parametric tests were used for analysis. The Mann–Whitney U test was used for comparing the differences between 2 groups and the Friedman’s ANOVA with Tukey’s post hoc tests for comparison between 3 and more groups. Results were considered statistically significant at Pseudomonas aeruginosa strains forming mucoid or non-mucoid colonies. Neither the differences in antibiotic susceptibility nor profile of genes associated with virulence influenced maturation of DCs. We found statistically significant  differences in percentages of fully matured DCs after stimulation with Pseudomonas aeruginosa strains isolated from patients with different courses of disease  and MFI of HLA-DR  between groups of Pseudomonas aeruginosa strains isolated from the patients with different clinical course of infections. A detailed paired analysis is shown in The individual characteristics of induction of HLA-DR expression on PBMC after stimulation with lysates of individual strains of Pseudomonas aeruginosa are summarized in The comparisons of percentages of CD3+CD4+ cells after stimulation with lysates of individual strains of Pseudomonas aeruginosa are summarized in The comparisons of percentages of CD3+CD4+IL-17+ cells after stimulation with lysates of individual strains of Pseudomonas aeruginosa did not reveal any statistically significant differences. We did not find any statistically significant associations between concentrations of IL-1β, IL-6, IL-8, IL-10 and TNF with antibiotic sensitivity of examined strains, mucoid or non-mucoid phenotypes of colonies, profile of genes associated with virulence or clinical course of infection.A comparison of concentrations of IL-1β, IL-6, IL-8, IL-10 and TNF after stimulation with the lysates of individual strains of Pseudomonas aeruginosa strains were isolated from five patients, and it was assumed that we were dealing with a situation where patients are affected by many severe co-morbidities and their immune system is impaired and undergoes complete collapse under the influence of infection. The second group of Pseudomonas aeruginosa strains were isolated from symptomatic patients with urinary tract infections, but without any comorbidity, and these patients were not immunocompromised. Their infections do not generalize into septicemia derived from the urinary tract, the so-called urosepsis. However, some kind of abnormal immune response may be suspected. The third group of patients were individuals who were asymptomatic carriers. In each of these groups, Pseudomonas aeruginosa infections with pathogens of different virulence may be expected, and analyses were performed to identify the main virulence factors of the bacterial strains in each of these groups. Conclusions on the association of immunological status of patients with virulence of individual strains of Pseudomonas aeruginosa must inevitably have to be indirect because we are unable to effectively, quickly and quantitatively determine the efficacy of the patient’s immune system as a whole—it is often difficult to pinpoint exactly where there is a deficiency of immunity in a patient without a congenital immune defect, which is associated with an opportunistic infection, and yet such deficiency is a fact. This difficulty also arises from the complexity of the immune system and the multiple interactions among its numerous components. We used PBMC of healthy donors to avoid the influence of the in vivo factors associated with patient condition, e.g., Systemic Inflammatory Response Syndrome in patients with systemic infections.In this work, an analysis was conducted to elucidate the question of which factor is more important, the immune status of the patient or the virulence of the pathogen. In the first group, Pseudomonas aeruginosa strains that colonize the urinary tract can have far-reaching consequences. This bacterium has a large predilection for adherence and growth in the form of biofilms on artificial surfaces in the body, including commonly used urinary catheters [Pseudomonas aeruginosa in these cases, but it should be assumed that this is a fairly common bacterium that causes these infections. For example, in a retrospective Japanese study, Horino and colleagues reviewed 134 cases of Pseudomonas aeruginosa over seven years, where the most common illness in the infected people was leukemia, and the most common starting location was the urinary tract (24.6%) [Pseudomonas aeruginosa are not uncommon, although this is definitely not the dominant bacterium in these cases. Sobczyk and colleagues estimate the incidence of urinary tract infections by this pathogen at 9% after Escherichia coli and Staphylococcus saprophyticus [Phagocytosis of the atheters . In addiatheters . Less wo (24.6%) . Ambulatphyticus . This inAfter the pathogen breaks through the non-specific immunity barrier, the infection can be countered by specific immunity, and it is this branch of the immune response that was assessed in our study. Pseudomonas aeruginosa lysates between the strains isolated from the most severely ill patients and from asymptomatic carriers. Zhang et al. identified the Pseudomonas aeruginosa Mannose Sensitive Hemagglutination Strain as an important exogenous factor that induced DCs maturation toward a Th1-promoting phenotype [Pseudomonas aeruginosa could be more efficient in the induction of DCs maturation. On the other hand, they generated dendritic cells from isolated CD14+ monocytes, and in our study, we used PBMC. In patients in poor general condition, where there is a collapse of the body’s defenses, it is highly probable that an ineffective response to this otherwise highly immunogenic Pseudomonas aeruginosa strain may be expected. Perhaps the differences observed are related to virulence of strains, so that bacteria that colonize the upper respiratory tract are potentially the least aggressive and are sufficiently controlled by the immune system also with minimal effort.Dendritic cells are the most potent antigen presenting cells that are able to efficiently induce primary T-cell-mediated responses to pathogens, including bacteria. The induction of dendritic cell maturation was confirmed in previous research ,14. We fhenotype . Their rPseudomonas aeruginosa isolated from critically ill patients. Avendaño-Ortiz J et al. showed that monocytes from patients with cystic fibrosis (CF) colonized by Pseudomonas aeruginosa exhibit a lower expression of HLA-DR+ (ratio between mean intensity of fluorescence (MIF) on LPS stimulated cells divided by MIF on unstimulated cells) than non-colonized patients [Pseudomonas aeruginosa, rather than with a particular strain of this bacteria.The increased expression of HLA-DR on the variety immune cells is associated with their activation and maturation. We found a significantly higher percentage of HLA-DR+ PBMC and highest expression after stimulation with the lysates of patients . The expPseudomonas aeruginosa strains and percentages of CD3+CD4+ cells after stimulation with bacterial lysates. The median percentages of CD3+CD4+ cells ranged from 34.37% to 42.78%. The lower percentage of CD3+CD4+ after incubation with lysates of particular strains could be associated with a higher concentration of alkaline protease (AP) or elastase (Ela) in the lysates. Pedersen et al. found that AP and Ela could specifically cleave CD4 molecules [We did not find any statistically significant associations between features of examined olecules .Pseudomonas aeruginosa. Liu and co-workers demonstrated a significant role for IL-17 in murine models, in addition to IL-22 and IL-23. In the development of acute inflammation of the lungs [Pseudomonas aeruginosa pneumonia. IL-17 plays a protective role in the early stages of infection, and its concentration rapidly increases during infection [Pseudomonas aeruginosa strains were found. Evaluation of the specific immune response to the tested strains of Pseudomonas aeruginosa brought several important conclusions. The first is that the specific response is less dependent on the features of particular Pseudomonas aeruginosa strains isolated from patients with different clinical courses of infection. This demonstrates that the specific response expressed in the effector phase is rather not significantly impaired by any of the examined strains of Pseudomonas aeruginosa. More detailed research is still underway on the extent to which the resulting antibody neutralizes the pathogen (as it may change its phenotype during infection) and to evaluate the response of the specific immune system to live bacteria. Creating a laboratory model of sepsis or bacteremia Pseudomonas aeruginosa remains an interesting experimental challenge.There are works in the literature on the role of IL-17 in the immune response to infections caused by he lungs ; based onfection . The higIn most patients, especially those infected by the pathogen, it is difficult to suggest an immune system test evaluating specific immune responses that would clearly indicate an immune system defect. In spite of these difficulties, it seems that we should not be satisfied with the diagnosis of the infection itself, but we should look for general and local factors that predispose the patient to it, especially if the patient is in a fairly good general condition or is suffering from recurrent infections. It may be possible to deepen our knowledge about the still unclear etiology of opportunistic infections and to identify factors favoring such infections both on the host side and on the pathogen side.Pseudomonas aeruginosa is probably the poor general condition of the patient. The induction of specific immune response to the tested strains of Pseudomonas aeruginosa is maintained when healthy donor cells are used. This provides a preliminary basis for considering the use of vaccination in patients with recurrent infections and coexisting risk factors. Moreover, strains responsible for the most severe infections effectively stimulate the immune system. In patients with good general condition but with recurrent infections of Pseudomonas aeruginosa, it seems appropriate to seek general and local factors conducive to the onset of this infection. Additional information may be provided by studies of immunity specific to live bacteria in laboratory models of infection caused by Pseudomonas aeruginosa.The most important factor in favor of severe generalized infections caused by


Although both long and short cephalomedullary devices (CMDs) are used in the treatment of extracapsular hip fractures, the advantages of either option are subject to debate. This study aims to evaluate the differences in clinical outcomes with long versus short CMDs for extracapsular hip fractures. Studies included must have included subjects with at least 1 year of follow-up and reported on at least one of the following outcomes: rate of reoperation; rate of peri-implant fracture; operating time; blood loss; complication rate; length of hospital stay; 1-year mortality. Only articles written in the English language were included in this study. A search was conducted across the databases of Medline, Embase, CENTRAL , CINAHL and Scopus for articles published from the inception of the database to 1 November 2020. Included studies were assessed for their risk of bias using the Risk of Bias Tool (RoB2) and the risk-of-bias in non-randomized studies – of interventions (ROBINS-I) tool. A total of 8460 fractures from 16 studies were included in the analysis, with 3690 fixed with short, and 4770 fixed with long CMDs. A meta-analysis of the results revealed that short CMDs offer peri-operative advantages, while long CMDs could offer longer-term advantages. Limitations of this study include a lack of randomized control trials included in the analysis. In conclusion, when planning for the treatment of extracapsular hip fractures, a patient specific approach may be necessary to make a decision according to the individual risk profile of the patient. Furthermore, with a 1-year mortality rate of about 20%, being able to choose the optimal treatment of a hip fracture is of increasing importance and relevance3. Of the different types of hip fractures, extracapsular fractures such as basicervical neck of femur fractures and intertrochanteric (IT) fractures are thought to be the most associated with falls from a standing height in elderly patients who have osteoporosis4.Hip fractures are known to be increasing in frequency globally due to an ageing and active global population, with annual incidences set to rise to 6.26 million by 20507. When compared with previous surgical options for management, CMDs have shown more favourable long term outcomes and a lower rate of complications8. CMDs which are < 250 mm in length are generally considered to be short, while those longer than 250 mm are classified as long CMDs, the difference being short CMDs do not cross the isthmus of the femur9.Currently there is an increasing trend towards the using a cephalomedullary device (CMD) to manage both stable and unstable extracapsular hip fractures (EHFs) as these nails act as an intramedullary buttress to prevent excessive shaft medialization11.Previous studies have compared the biomechanical properties of long and short CMDs and their effectiveness in fixation of EHFs. While it has been found that axial stiffness is greater in the use of short CMDs, the overall results show no significant differences between short or long CMDs and suggest that either option can be employed for fixation of unstable EHFs12. In recent years, research into this topic has shown advantages of short CMDs over long CMDs, with better intra-operative outcomes, including a shorter operative time, less blood loss and lower rate of transfusion14. Conversely, there are also advantages for the use of long CMDs over short CMDs. The longer nail length theoretically provides increased stability in unstable patterns due to the possible distal subtrochanteric extension15. There have also been lower reported rates on the incidence of peri-implant fractures, possibly due to the full-length nail providing protection to the entire femoral shaft17. But these differences have not affected long term outcomes in patients, with both groups showing no significant difference in reoperation rates, complication rates or 1-year mortality rates19.Although both long and short CMDs are used in the treatment of EHFs, the theoretical advantages of either option are subject to debateHowever, these findings have not been clearly shown in large scale review papers and meta-analyses. This systematic review and meta-analysis of current literature aims to evaluate the differences in clinical outcomes with long versus short cephalomedullary devices (CMDs) for extracapsular hip fractures with the primary outcome being operative time and secondary outcomes being complications such as blood loss and peri-implant fractures.The systematic review was planned, conducted, and reported according to the PRISMA guidelines.To be included in this study, articles had to be either randomized controlled trials, retrospective or prospective cohort studies. These studies must have also reported on simple or multifragmentary EHFs  and compared results from patients treated with long CMDs versus short CMDs. The studies must have also had subjects with at least 1 year of follow up, and reported on at least one of the following outcomes, operating time; estimated blood loss; length of hospital stay; overall rate of peri-implant fracture; overall rate of reoperation; overall complication rate; 1-year mortality. Only articles written in the English language were included in this study.Case reports, case series, systematic reviews and meta-analyses were excluded from this study. Additionally, articles which did not include both short and long CMD cohorts for comparison, had less than 1 year follow up, or included pathological fractures due to tumours were also excluded , CINAHL and Scopus for articles published from the inception of the database to 1 November 2020. The search strategy used was based on: (Hip Fractures or Intertrochanteric Fractures or pertrochanteric fracture*) and .Duplicate studies were identified and removed by Covidence, a systematic review tool which uses the Cochrane technology platform. Two independent reviewers then screened the identified studies for relevance. Full manuscripts of included studies were assessed according to the eligibility criteria and the data was extracted. Any inconsistency was resolved through discussion between the two reviewers.p value of < 0.05 was considered significant for this study.All statistical analyses were performed using Cochrane Revman 5.3 Software (Cochrane Collaboration 2014). Risk ratios and 95% confidence intervals were calculated. A . with 5526 patients20. Detailed information on the studies included are included in Table A total of 4143 studies were identified through the database searches, with 16 meeting the inclusion criteria and being included in this study Fig. . A total., Okcu et al. and Shannon et al., had a randomised controlled trail (RCT) design33. The remaining thirteen studies were retrospective cohort studies. Half of the studies were performed in the USA, with the remaining from Europe and Asia.Three studies, Sellan et al., which opted to include the Gamma 2 nail as a choice of long nail despite not including it under the short nail devices23.Data on the device models were collected from most studies, demonstrating a wide spectrum of device preferences across the board. Majority of the studies used a fixed device brand with nails of varying length for comparison, with the notable exception of Kleweno et al. noted a significant preponderance of females over males18. Boone et al. and Guo et al. also included significant differences in the ages of patients offered short and long nails, with older patients tending towards a short nail26. The included studies have a range of mean follow-up duration of 10.2–40.6 months post-operatively. Additionally, each study had at least one patient who was followed up for a minimum of 12 months post-operatively. ASA score was reported in four studies, ranging from 1 to 430.Most of the included studies had largely similar demographics of gender and age. However, Hou et al. only studied patients with 31A3 fractures28.Twelve studies reported on the fracture classification, with ten further subclassifying the fractures under the length of nail used. Many (n = 6) focused on 31A1/2 fractures, but some studies (n = 4) also elected to include patients from all 31A fractures. Of note, Okcu et al33.Twelve studies included data on operative times for the surgical procedures. All but one study reporting a significantly longer operating time for long CMDs as compared to short CMDs, with Hong being the only dissenting study33. Five studies included information on the number of patients requiring blood transfusion, however only Boone et al. reported that there was a statistically significant difference in transfusion rates31.Eight studies reported on the estimated blood loss from either procedure, with 7 studies reporting statistically significantly higher mean estimated blood loss in long CMD operations as opposed to short CMDs31.A total of 9 studies included the LOS of patients post-operatively, with 8 of the studies reporting no significant difference in LOS between the two groupsInformation on intraoperative results have been reported in Table 31.Seven studies reported on the 1-year mortality rates of patients, with none of them finding any significant difference between the two groups. reporting statistically fewer incidences in the long CMD group33.1-year complication rate was reported in 11 studies, with only Li et al33.The 1-year reoperation rate was reported to be statistically similar in the 8 studies which included the information33.Peri-implant fracture rates 1-year post-operatively were reported in 10 studies, with only Frisch et al. reporting a statistically higher rate of fractures on the short CMD group33.Peri-implant infection rates 1-year post-operatively were also reported to be similar in the 6 studies which reported on them. reported a significant difference between the groups, with the short CMD group reporting higher results33.Only three studies noted patient reported outcomes under the Harris Hip Score 1-year post-operatively. Of the studies, only Shannon et alDetailed information on post-operative results and complications can be found in Table We performed a meta-analysis to compare several outcomes of interest between long and short CMD groups. The outcomes analysed were mean operating time, mean estimated blood loss, mean length of stay, peri-implant fracture rates, reoperation rates and 1-year mortality rates. All 16 included studies were included in the meta-analysis.p value < 0.00001)   Fig. .Figure 4p value = 0.23)  times as likely as the risk among patients who had long CMDs  times as likely as the risk among patients who had long CMDs  times as likely as the risk among patients who had short CMDs  to 47% (33/70), with the vast majority reporting rates of under 30%. The decrease in 1-year mortality rate could reflect an improvement and development in operative technique, and post-operative care of hip fracture patients, thereby improving the prognosis.Finally, the 1-year mortality rate between the groups was found to be similar, with no significant difference between them. While the 1-year mortality rate has been reported to be as high as up to 58%, the current study has found significantly lower mortality rates across the groups26.Most studies included in this study have been deemed to have low levels of bias. However, those papers which have been identified to have potential issues with bias are commonly due to confounding variables, which most commonly are due to a significant difference between the ages of the short and long CMD groups. The studies which had these differences postulated that the difference could be attributed to shorter operative time which would be favourable in older age groups40. However, this should also be weighed against benefit in long-term outcomes that have been shown with the use of a long CMD.In light of our analysis, we postulate that the use of short CMDs may be better suited for high-risk patients who may not be able to tolerate longer operating times. This includes those who have multiple medical comorbidities, and the elderly. The decrease in the amount of time under anaesthesia could be advantageous for these patients as it may decrease the risk of perioperative complicationsWhile the study has presented several findings that could help guide the decision between the use of a short or long CMD, the strength of this study is in the volume of patients included in the analysis. This is the largest meta-analysis on the topic thus far, with the inclusion of large multi-centre data in the pooled analysis. Limitations of the paper would include the lack of RCTs included. While there were 3 included in the analysis, a larger pool of RCTs would be helpful in ascertaining the differences between short and long CMDs. Additionally, there was limited data available for some of the outcomes of interest, including 1-year post-operative HHS and transfusion rate, preventing a pooled analysis on these outcomes. Furthermore, the mean follow-up period of the included studies was varied (10.2–40.6 months), making a cross sectional study of the outcomes of interest difficult. While a key point of interest would be to investigate incidence and timeline of peri-implant fracture rates, few studies reported the time to the incidence of peri-implant fracture. This precluded further analysis on this subject, and the current study is only able to draw a conclusion to the overall rate of complications and peri-implant fractures. Other potentially interesting areas of further research on this topic would include a comparison between the peri-implant fracture rate in different periods post-operatively, including short- and long-term studies on the topic.Short CMDs offer advantages of shorter operative time and lesser blood loss. However long CMDs could offer longer-term protection against peri-implant fractures. Therefore, in planning for the operation, a patient specific approach may be necessary to make a decision according to the individual risk profile of the patient.Supplementary Information 1.Supplementary Information 2.Supplementary Information 3.Supplementary Information 4.


In the present study we combined popular methods of sports vision training (SVT) with traditional oculomotor protocols of Optometric Vision Therapy (OVT) and electrophysiological indexes of EEG and VEP activity to monitor training progress and changes in performance of youth ice hockey players without the history of concussion. We hypothesized that administration of OVT protocols before SVT training may result in larger performance improvements compared to the reverse order due to the initial strengthening of visual hardware capable of handling greater demands during training of visuomotor integration and information processing skills . In a cross-over design 53 youth ice hockey players (ages 13–18) were randomly assigned to one of the two training groups. Group one (hardware-software group) completed 5 weeks of oculomotor training first followed by 5 weeks of software training. For group 2 (software-hardware) the order of procedures were reversed. After 10 weeks of training both groups significantly improved their performance on all but one measure of the Nike/Senaptec Sensory station measures. Additionally, the software-hardware training order resulted in significantly lower frontal theta-to-gamma amplitude ratios on the Nike/Senaptec test of Near-Far Quickness as well as in faster P100 latencies. Both training orders also resulted in significant decreases in post-treatment P100 amplitude to transient VEP stimuli as well as decreased theta-gamma ratios for perception span, Go/No-Go and Hand Reaction time. The observed changes in the electrophysiological indexes in the present study are thought to reflect greater efficiency in visual information processing and cognitive resource allocation following 10 weeks of visual training. There is also some evidence of the greater effectiveness of the software-hardware training order possibly due to the improved preparedness of the oculomotor system in the youth athletes for administration of targeted protocols of the Optometric Vision Therapy. Which comes first in Sports Vision Training: the software or the hardware update? Utility of electroencephalographic measures in monitoring specialized visual training in youth athletes.Over the past several decades, there have been numerous studies involving training or enhancement of normal vision function with the almost unanimous conclusion that most visual functions can be improved by specific laboratory-based vision training paradigms , dynamic depth perception, perception span and reaction time were able to predict 69% of variance in goals scored by these players in the subsequent 2 hockey seasons  measures may prove particularly useful in assessing effects of sports vision training on visual processing. For example, Zwierko et al.  previousstatic and dynamic visual acuity, depth perception, accommodation, fusion (convergence), color vision, and contrast sensitivity. Ferreira  may be compromised due to a previous history of concussion  protocols of Optometric Vision Therapy. We hypothesized that our electrophysiological indexes of EEG and VEP activity previously used in research with athletes with a history of concussion  were recruited from local and public school extra-curricular athletic programs in ice hockey via their respective activities directors and athletic program directors. The study protocols were approved by the Institutional Review Board (IRB) of the University of North Dakota. The participation was voluntary, and the participants had the right to withdraw any time from the study.Eighteen participants reported having had at least one lifetime concussion . Eight of these youth athletes reported having had their most recent concussion in the past year, while the remaining 10 indicated having had a concussion over a year before their participation in the study. None of the participants with a history of concussion reported any lasting symptoms and all of them resumed their regular athletic and academic activities following their most recent concussion. Training results of these participants were excluded from the analyses as our previous research as well as study findings of others showed that athletes with a history of concussion may differ from age, gender and sport- matched controls on some of the measures of the Nike Sensory Station  is provided in our earlier paper . In addition to the original 4 featured in the Nike SST, the Senaptec system also trains dynamic vision, sensory memory, response inhibition, spatial memory, spatial sequence, multiple object tracking, near far shirt, visual search, tempo, shape cancellation and visual motor integration.In the present study we utilized the B-Alert X10 device  for wireless EEG recording along 9 channels that collect continuous electroencephalographic signals from electrode locations in the frontal , central , and parietal-occipital  areas. These electrode locations are predetermined by distances between sensors on a 9-sensor strip. The size of the strip is selected based on the distance between the subject's nasion and inion. As per manufacturer's recommendation, the medium strip was used for subjects with nasion-inion distances >34.5 cm and the small strip was applied when the distance was between 32.0 and 34.5 cm. Using these guidelines, sensor locations correspond to the International 10–20 system of scalp electrode placement. Disposable self-adhesive sponge electrodes filled with 0.4–0.6 cc of Synapse® conductive electrode cream were attached to the sensor strip before the headset's placement on the participant's scalp. Two mastoid leads with disposable electrodes served as reference and were placed over the participant's mastoid bones on each side of the head.The B-Alert X-10 has a 256 Hz sampling rate and sends radio signals using a 2.4 to 2.48 GHz radio transmitter to the B-Alert X-10 Live acquisition software that can be run from any PC using a USB receiver. Prior to signal transmission the unit also performs analog-to-digital conversion, encoding, and formatting.Data were sampled and processed at 256 Hz using a band pass filter from 0.5 to 65 Hz (3 dB attenuation). Notch filters at 50, 60, 100, and 120 Hz were used to specifically target the removal of environmental noise  not fully attenuated by the band pass filter. The EEG signal was referenced to the linked mastoid-placed electrodes using the average voltage between the reference electrodes. The acquisition software used ABM algorithms to detect and remove artifacts  prior to power spectral density (PSD) computations. PSD was automatically computed by the B-Alert Live software using a 50% overlapping window across three, 1-s data overlays (256 decontaminated data points each) and applying the Fast Fourier Transformation with Kaiser windowing for data smoothing. If more than 128 zero values were inserted for an overlay, the overlay was excluded from the epoch average; if 2 of the 3 overlays were rejected, the epoch was classified “invalid” excluded from analysis.This resulted in PSD values for each 1-s epoch for 1 Hz frequency bins ranging from 1 to 40 Hz. PSD values were then log10 transformed by the software to achieve a Gaussian distribution. Relative PSDs were computed automatically by taking the PSD value in the 1 Hz frequency of interest and dividing it by the sum of the PSD values from 1 to 40 Hz. To obtain bandwidth frequencies, the relative 1 Hz PSD bins were averaged across the frequency ranges as follows: 3–7 Hz (theta), 8–12 Hz , 13–19 Hz (low beta), 20–29 Hz (high beta), and 30–40 Hz (gamma).A short-term memory load index (STMLI) was then calculated for each participant and each Nike SST task by dividing relative PSD for theta at Fz by the corresponding relative PSD for gamma, resulting in STMLI ratios for each 1-s epoch (see Formula 1).Formula 1. Calculation of the Short-term Memory Load IndexFor each Nike SPARQ test, 1-s epochs of STMLI ratios were aggregated using 5% trimmed means for each participant . Five percent trimmed means were used to eliminate 1-s epoch with extreme values.Transient VEPs (tVEP) were obtained using a Diopsys NOVA System . The stimuli were presented on an Acer V173 43.18 cm LCD monitor (33.7 cm × 27 cm) with a refresh rate of 75 Hz. The stimuli included 2 checkerboard and 2 vertical sine wave gratings.2 and were reversed 2 times per second .The checkerboard stimuli were of two sizes: 8 × 8 with 3.38 cm (2-degree check size) and 16 × 16 with 1.69 cm checks (1 degree check size). Both checkerboard patterns had a Michelson contrast of 85%, mean luminance of 102.22 cd/m2. The 0.25 and 0.50 cycle/deg gratings had a total of 4 and 8 cycles, respectively. Note that the physical width of each half cycle of the 0.25 and 0.50 cycle/deg gratings was equal to the width of the 2 and 1-degree check sizes, respectively ; 0.25 cycle/deg vertical sinusoidal grating (three times); 1 degree checkerboard (three times); 0.5 cycles/deg vertical sinusoidal grating (three times).Analog signals were amplified by a factor of 20000 , band-pass filtered with cut-off frequencies of 0.5–100 Hz and sampled at 1,024 Hz for the checkerboard pattern (512 data points) and 2,048 Hz for the vertical sine patterns .The module automatically measured signal-averaged latency of the exogenous P100 component of the typical N75-P100-N135 complex in response to visual stimulus presentation. This latency represents conduction time between retinal stimulation and excitation of neurons in the primary visual cortex. In the context of the present study and consistent with the manufacturer's nomenclature the term “latency” refers to time to the first major positive peak occurring around 100 ms (P100). The module also provided relative amplitude measurements in the form of the difference between the N75 and P100 (delta N75-P100), which is thought to address issues of individual variability attributed to anatomical differences and electrical properties of the testing environment. VEP extraction for this system was previously described by Tello et al.  and is bOne of the commercially available clinical devices/software is the VTS4, that is, Vision Therapy System version 4 . VTS4 is commonly used in optometric/ophthalmologic practices that specialize in binocular vision. VTS4 is used for both diagnosing  and for managing binocular vision anomalies . VTS4/Computer Orthoptics includes complex monocular and binocular stimuli, which allow automatic testing and measurement of the following skills: Oculomotor (pursuits and saccades); fusional vergence ranges; heterophorias; motor fields; fixation disparities, suppressions; retinal correspondence; accommodative facility; stereopsis, visual memory and Aniseikonia. VTS4 uses liquid crystal glasses with dichoptic stimuli that are synchronized to each eye through rapid alternating occlusion to help train the patient. Included, are several random dot stereograms and other stereo targets which are devoid of monocular cues and can be seen only during binocular vision, thus ensuring patient compliance. Specific therapy procedures are designed to improve smooth (ramp) vergences, jump (step) vergences, positive and negative accommodation, pursuits, saccades, sensory fusion, and visual memory.The Neurotracker Training system was developed by CogniSens Inc. in collaboration with the National Hockey League and US NCAA to train visual perception span, split attention and decision-making. The program presents randomly moving spheres in 3D space at variable speeds. Four spheres are targeted for tracking and then blend with another four. Repeated trials following a staircase procedure allows athletes to both expand the amount of movement information they can absorb in the field and process that information more efficiently until a training speed threshold is established. As a result of this training, the athlete is able to decrease their anticipatory response time in terms of reading the play, make quicker decisions during play action and increase the time available to choose the best play option  eyewear uses battery-powered liquid crystal filtered lenses that alternate between transparent and opaque states and provide varying lengths of occlusion that are under the control of the participant. The transparent state consists of complete visibility while the opaque state consists of a medium gray that is difficult to see through. The strobe effect is defined by opaque states that can be changed through eight different durations, ranging from 25 to 900 ms of visual occlusion, while the transparent state is fixed at a constant 100 ms , developed by Robert B. Sanet and Rodney K. Bortel is a training software available as a computerized system through HTS, INC. It is widely used in clinical optometry and optometric vision therapy to evaluate visual guidance of motor performance and offers five primary programs used for vision training. These programs include: Eye Hand, Rotator, Metronome, Saccades, and Tachistoscope. For the purposes of the present study we used the Rotator, the Saccade and the Tachistoscope modules.The Rotator module combined 4 rotator programs that work on various aspects of visual ability including Eye-Hand Coordination, Visual Reaction Time, Hand Speed and Accuracy, Peripheral Awareness, Central-Peripheral Integration, Bilateral Integration, Pursuits, Saccades, Visual Acuity Enhancement, Anti Suppression-Monocular Fixation in a Binocular Field (MFBF), Contrast Sensitivity, Vision Directing Action, Visual-Auditory Integration and Sequencing. For the purposes of the present study we used Rotator 1, 2, and 4 programs. In Rotator I targets remain on a virtually rotating screen until the stimulus is touched. The size, color, and shape of the stimulus as well as the speed of the virtual screen rotation can be manipulated within this level. In Rotator II visual target classification and sequencing are added. At this level rotating targets are of different colors and the task is not only to quickly and accurately touch specific targets but to do so in the proper order . In Rotator IV the stimuli are upper- and lowercase letters and numbers. These targets need to be hit in a specific order .The saccade module was used for saccading training and included Saccade 1, Saccade 2, and Verbal 1 programs. With Saccade 1, the subject stands in front of a 46-inch touch-screen where various non-duplicated numbers or letters are scattered across the screen. The subject is to rapidly search the screen and touch each number or letter in sequence until all the numbers/letters are gone. In Saccade 2, a single number, letter or word is briefly flashed at a random position somewhere on the screen. The subject must make a foveal saccade to locate the target and accurately call out the target that was flashed. When words are used, there are 200 common sight words that can be automatically flashed to further aid in word coding. The verbal mode is similar to the Saccade 1 program. A large number of numbers or letters are scattered across the screen. The computer calls out the number/letter to be touched and the subject tries to find and touch each number as it is called out by the computer until all the numbers/letters on the screen are gone.Finally, the Tachistoscope module is designed to train the following visual abilities: Speed and Span of Recognition, Visual Memory, Auditory memory, Auditory-Visual Integration, Visualization, Visual Search, Saccades, Visual Cognitive, Divided Attention. In this module various target stimuli can be used such as letters, numbers and words. The variable stimulus sequence is briefly presented centrally and then disappears, after which elements of the sequence are randomly presented in both central and peripheral screen locations. The goal is to touch the stimulus target in the right sequence (or reverse sequence from the standard).The Quick Board is a visual motor training technology intended to improve agility and balance. Quick Board's methodology was designed to improve and restore characteristics that are critical to athletic performance by enhancing motor learning with real-time feedback during exercises. It consists of a 41” × 31” × 1 HD Sensor Board with 5 circular targets and an iPad connected to the board. Quick Board's software allows athletic trainers and therapists to customize training protocols based on the subject population . Exercises and protocols provided in the software target reaction, speed, quickness, stability, coordination, balance, and proprioception. The device can also administer Go/No-Go type of tasks when sensor targets appear in different colors requiring differential motor output from the trainee. During the exercises, Quick Board's software displays real-time feedback on the iPad so that the subjects train with their eyes focused on the iPad, not looking down at the sensor board. Galpin et al.  reportedn = 8 in the present study) wireless, RGB LED powered lights that are used as targets for the user to deactivate as per the reaction training routine. These training lights can be mounted to walls, poles, and other training equipment or they can be strategically placed on the ground for specific training routines. Each light is controlled via an app. The app can be installed on any hand-held Android or Apple device and is available through the Google Play and App Store. During setup, users can program the lights using one of the built-in programs. Users can also modify programs or create unique regimens themselves. Once the user has selected their desired program, they can begin using the lights. During any type of training, specifically, speed and agility training, the lights can be deactivated by use of the users' hands, feet, head, or sport/fitness/healthcare related equipment. The deactivation of the lights can be achieved through full contact or proximity–waving, running past, swiping, etc. Captured performance data  are available for each individual athlete in a time series (over multiple training session) and can be used for subsequent group analysis. This system has been recently reported to produce improved neuromuscular control in Russian University-level basketball players characterized by a 43.6% reduction in ball control errors during dribbling , near visual acuity (Reduced Snellen Chart) and non-cycloplegic manifest refraction. If significant refractive error was discovered (≥+1.00 sph or −0.50 sph or ≥-0.75 cylinder) the subject was fitted with MyDay daily disposable contact lenses (Cooper Vision) to achieve at least 20/20 vision in each eye. Through these lenses we measured: distance phoria (Von Graefe); near phoria (modified Thorington); nearpoint of convergence (NPC using Bernell Rule); monocular accommodative pushup amplitudes (Bernell Rule); vergence facility at near (3BI/12BO prism); accommodative facility (+2.00/−2.00 flippers) phoropter-based near testing including negative relative vergence; positive relative vergence; positive relative accommodation; negative relative accommodation; and phoropter-based associative vergence measures and Nearpoint of Fixation Disparity (NPFD by Vision Assessment Corporation). The full description of oculomotor protocols used in the present study can be found in Poltavski and Biberdorf .After the optometric evaluation participants underwent VEP testing. The VEP recording utilized a 3-electrode montage using Diopsys skin electrodes. The active electrode was placed ~4 cm above the inion in the Oz location according to the International 10–20 system  while the reference electrode was placed about 10–11 cm above the nasion . The left side of the forehead  served as ground. In preparation for recording, the skin at each electrode site was scrubbed with Nuprep  on a cotton-tipped wooden swab. Electrodes were fixed in position with Ten20 conductive paste  and secured with a small gauze pad with conductive paste applied. Electrode impedance was maintained below 10 k ohms in all cases and was usually below 5 k ohms.Each subject was instructed to sit comfortably and steadily about 1 meter from the test screen and centered along the midline at eye level and blink normally during the procedure. Per the manufacturer's software, a small (0.25° radius) red rotating, annular fixation cross target was presented in the center of the test screen to control accuracy of fixation and accommodation as well as to maintain visual attention. Subjects were instructed to fixate upon the small central target with minimal blinking to reduce any response artifacts. Three 20-s trials were conducted for each stimulus type  and size (0.25 cycle/deg vs. 0.50 cycle/deg). The participant had to complete all 3 presentations of the same pattern before proceeding to the next one. Trials were separated by ~3-s breaks. During the breaks the experimenter encouraged the participant to continue looking at the center of the screen at the fixation target and manually initiated the next trial. Each pattern was thus presented for 1 min resulting in the total of 4 min of VEP recording.All Nike SST/Senaptec and EEG testing sessions were completed after the optometric and VEP evaluation and on a separate day. Upon arrival to the lab, each participant was fitted with the EEG sensor strip that was plugged into the B-Alert X-10 wireless sensor headset. Once all channel impedance values were below the manufacturer recommended 40 kΩ, each participant first underwent a 15 min neuropsychological evaluation consisting of three 5 min computerized tasks programmed by the manufacturer of the acquisition software (ABM) to automatically generate cognitive state metrics (these statistics were not utilized in this study).Following completion of the benchmark tests, participants underwent the Nike SST/Senaptec assessment. Each station test was preceded by a brief practice session that included several trials. Within the B-Alert X-10 Live Acquisition software, the continuous EEG stream was broken into intervals corresponding to the beginning and end of each Nike SST task by manually inserting start and end markers during acquisition. Once the participant completed all the tasks, acquisition of EEG signals was terminated, the headset and the sensor strip were removed, the participant was debriefed and dismissed. Each assessment session lasted on average 60–65 min.The subjects were randomly assigned to one of the two training protocols. Both protocols involved two 1 h training sessions per week for 10 weeks resulting in a total of 20 h of combined training per subject. Group one (hardware-software group) completed 5 weeks (10 h) of oculomotor training first followed by 5 weeks (10 h) of software training. For group 2 (software-hardware) the order of procedures were reversed. All training procedures were administered by the same Optometric Vision Therapist (OVT)/SVT trainer who was also Nike-certified in Sensory station training and testing.Visual hardware training was based on the general principles and guidelines for office-based vision therapy (VT)/Orthoptics developed by the Convergence Insufficiency Treatment Trial (CITT) Study Group . This prhttps://optometry.osu.edu/CITT-manual-procedures).The following techniques and activities were used to accomplish these goals in different phases. Brock String and Barrel Cards were used in Phase I for gross convergence training. Vectograms (Quoits/Clown) Base Out, Computer Othoptics  and Life Saver Cards were used in Phase 1 for fusional vergence training. Loose Lens Accommodative Rock, and Letter Chard Accommodative Rock were used in Phase I for accommodative training. In Phase II Fusional Vergence training was further developed with Vectograms (Quoits/Clown), Computer Orthoptics , Aperture Rule and Eccentric Circles. Accommodative training in Phase II was implanted using the Loose Lens Accommodative Rock, Accommodative Flippers and the Letter Chart Accommodative Rock. In Phase III jump vergence procedures were used for fusional vergence training with the following techniques: Vectrograms (Quoits/Clown), Computer Orthoptics (VTS4), Aperture Rule, Eccentric Circles and Loose Prism Facility. Accommodative training goals in Phase III were accomplished using Binocular Accommodative Flippers. Detailed procedures for administration of these techniques are described in the Convergence Insufficiency Treatment Trial Manual of Procedures , the Quick Board, the Fitlight and the Neurotracker Core Training Session, slide board and rubber board drills. The Nike Vapor Strobe glasses were used during the Eye-Hand Coordination and Go/No-Go training sessions at different Levels starting from Level 1 up to Level 8 and were added to the training following week 1 (after 2 h of training on the four modules). When the strobe glasses were used the Eye-Hand Coordination and the Go/No-Go modules were be completed twice: once without the glasses and once with the strobe glasses on. These Nike activities were practiced during all software training sessions with the difference in the speed of stimulus presentation and the Level of the Nike Vapor Strobe glasses. After the first 2 weeks of training (after 4 h) the challenge level of these activities was further increased by placing participants on the balance ball.Following completion of the Nike training module activities, participants proceeded to the Quick Board, which was also used in combination with the Nike Vapor Strobe Glasses (added to the regimen after week 1) and a hockey stick with a padded blade to make visual drills more sport-specific. Various sequences of lit-up targets on the board had to be touched both with the left and right feet as well as the hockey stick with and without Strobe Glasses. After the Quick Board activities, the participants moved on to the Fitlight training. A random setup sequence of 8 Fitlights arranged on the floor was used in hockey-specific training drills when the study participants were asked to use a hockey stick with the padded blade to hit each randomly illuminated target once with the Nike Vapor Strobe glasses on and once without the glasses.After the Fitlight drills, the participants completed 8 min of the Neurotracker Core Training Session with variable speeds, which depended on the subject's accuracy during a preceding trial . Then the participant was placed on a sliding board and would start sliding side to side while the therapist/trainer (positioned 10 feet away) would throw a tennis ball at the subject to the side to which the subject was moving. The objective of the activity was to catch the ball and to throw it back to the trainer while sliding. The activity took 2 min to complete and was intended to mimic eye-hand coordination demands while ice-skating. During the second minute Nike Vapor Strobe Glasses were added to the activity set at Level 1 or 2. The final activity of round 1 included practicing catching a rubber ball on an elastic string affixed to the wrist of the throwing hand of the subject for 4 min. The objective would be to bounce the ball off the floor and catch it. Each subject would switch hands after 1 min. Following the first 2 min the Nike Vapor Strobe Glasses set at level 1 or 2 were added to the drill. After these activities were completed the subject would repeat the cycle (Round 2). Completion of round 2 signified the end of the training session. It took on average 1 h to complete all of the activities in rounds 1 and 2.For assessment of performance changes on the Sensory Station measures as a function of training (time) and training protocol type (treatment) we combined data from equivalent measures of the Nike SPARQ Sensory System and the Senaptec Sensory station and included it into overall analyses. The within-subject variability was maintained for each station, so that error variance attributable to potential discrepancies in measurements between the two systems was not part of within-subject variance .Our 2 treatment groups did not significantly differ on any of the baseline measures of the Nike/Senaptec Sensory Stations, STMLI ratios or VEP  and amplitudes (μV) of the N75-P100-N135 complex (henceforth referred to as P100) in response to the two checkerboard and two vertical sinusoidal grating stimuli. Each stimulus was associated with 3 outcome response measures of latency and amplitude: fastest response to the type and size of the stimulus, medium response and slowest response. We averaged response latencies and amplitudes over the three responses and used the resultant means as dependent measures. Our preliminary diagnostics showed significant deviations from normality for most latency and amplitude variables based on significant Kolmogorov-Smirnov and Shapiro-Wilks tests as well as positive skewness statistics exceeding 2 standard errors for most variables. Thus, prior to statistical analyses all VEP variables underwent log10 transformation to minimize issues with normality and univariate outliers. This type of transformation is recommended for substantial issues with normality as identified by the shape of the distribution and corresponding z-scores of deviation statistics of skewness and kurtosis >3.29  separately for four log10-transformed latency variables  and corresponding 4 log10-transformed amplitude variables. Time of assessment  was the within-subject variable and treatment order (hardware—software or software-hardware) was the between-subject variable. Normality of the distributions for the log10-transformed variables was verified by comparing z-score values for skewness and kurtosis against the critical value of 1.96 at alpha level of 0.05.Power calculations were based on follow-up univariate Repeated Measures Analyses of Variance looking for interaction effects for within-and-between subject variables on any given dependent measure. Using G-Power 3.1  indicated a violation of the homoscedasticity assumption for dependent variables. Therefore, multivariate significance was assessed by evaluating significance levels associated with the F statistic for Pillai-Bartlett Trace test as a more robust measure to the violation of the homogeneity of covariances assumption. The results indicated multivariate significance for the main effect of time . This multivariate effect was associated with sufficient statistical power (1.00) and a moderate effect size . Neither the effect of treatment order, nor the order × time interaction were significant (see A significant Box's M test (F = 1.33 cant see .p = 0.16), so sphericity was assumed. The significant main effect of time  was associated with a small effect size (η2 = 0.07) and sufficient power (power = 0.77). Pairwise comparisons with the Sidak adjustment showed a significant progressive decrease in the Logarithm of the Minimum Angle of Resolution (logMAR) that reached statistical significance at alpha = 0.05 between baseline  and final assessment  indicating improved visual acuity.Univariate analyses showed that the multivariate significance for the main effect of time was significant for visual acuity and depth perception but neither of the two variables of contrast sensitivity. Mauchly's test of sphericity was not significant for visual acuity (p < 0.01) indicating a significant violation of the sphericity assumption  for that variable and requiring an epsilon (ε) adjustment of the degrees of freedom for the corresponding F-test. Since the Greenhouse-Geisser ε was >0.7 for depth perception, the Huyhn-Feld ε-adjusted F statistic was used to assess significance of the univariate test . Pairwise comparisons with the Sidak adjustment showed a significant progressive improvement in depth perception as indicated by a decrease in the threshold (arc sec) necessary to achieve stereopsis. These differences were significant between baseline and  and the mid-point assessment  and between the 5 week assessment and the 10 week evaluation . These results are summarized in Mauchly's test of sphericity was significant for depth perception  = 9.88, p < 0.01]. This multivariate effect was associated with sufficient statistical power (1.00) and a moderate effect size . Neither the effect of treatment order, nor the order × time interaction were significant.The results indicated multivariate significance for the main effect of time  for near-far quickness was associated with a small effect size (η2 = 0.24) and sufficient power (power = 1.00). Pairwise comparisons with the Sidak adjustment showed a significant progressive improvement in the mean number of correctly identified targets between baseline  and the 5 week assessment  and between the 5 week assessment and the final evaluation  . Mauchly's test of sphericity was not significant for either dependent variable, so sphericity was assumed. The significant main effect of time  was associated with adequate power (power = 0.79) and a small effect size . Pairwise comparisons with the Sidak adjustment showed a significant progressive improvement in the time (ms) required to correctly identify the direction of the opening in the Landolt ring. These differences were significant between baseline and  and the final assessment . These results are summarized in The significant main effect of time for dynamic visual acuity . Pairwise comparisons with the Sidak adjustment showed a significant progressive increase in the Go/No-Go total score from baseline  to the mid-point assessment  and from the 5 week assessment to the 10 week evaluation . These results are summarized in Univariate analyses revealed that the multivariate significance for the main effect of time was significant for all of the individual dependent variables. Mauchly's test of sphericity was not significant for all but one DV  indicating a significant violation of the sphericity assumption  = 82.21, p < 0.01, power = 1.00, partial η2 = 0.62]. Pairwise comparisons with the Sidak adjustment showed a significant progressive decrease in the time required to respond to all 80 targets expressed in milliseconds. EHC time significantly decreased from baseline  to the mid-point assessment  and between the 5 week assessment and the final 10 week evaluation . These results are summarized in A significant univariate main effect of time was observed for Eye-Hand Coordination . Pairwise comparisons with the Sidak adjustment showed again a progressive decrease in the average response time to a target stimulus expressed in milliseconds. Hand response time significantly decreased between baseline  and the 10 week assessment . The 5-week assessment HRT showed an intermediate value  that failed to reach significance when compared to baseline (p = 0.73) and barely missed significance compared to the final assessment (p = 0.52). These results are summarized in A significant univariate main effect of time was observed for Hand Response Time . Pairwise comparisons with the Sidak adjustment showed a progressive increase in perception span (PS). PS total scores were significantly greater at the 5 week assessment point  and the final 10 week assessment  compared to baseline  but did not differ significantly from each other (p = 0.73). These results are summarized in A significant univariate main effect of time was observed for Perception Span  but not for depth perception or contrast sensitivity. Pairwise comparisons with the Sidak adjustment showed a significant progressive decrease in the STMLI ratios over time that reached statistical significance at alpha = 0.05 between baseline  and final assessment .The results indicated multivariate significance for the main effect of time  = 2.61, p = 0.03; power = 0.72; partial η2 = 0.06]. Neither the effect of treatment order, nor the effect of time were significant. Univariate analyses showed that the multivariate significance for the time × treatment order interaction was only significant for the measure of near-far quickness  but not dynamic visual acuity (target capture). This significant time x treatment order interaction was further broken down by simple-effects analyses on near-far quickness within order. A significant main effect of time was observed for the software-hardware training order . Pairwise comparisons with the Sidak adjustment showed that STMLI ratios were significantly lower than baseline  after both 5  and 10 weeks of training . There was no significant main effect of time within the hardware-software training order  = 3.56, p = 0.01; power = 0.85; partial η2 = 0.15]. Neither the effect of treatment order, nor the order × time interaction were significant. Univariate analyses showed that the multivariate significance for the main effect of time was significant for STMLI ratios on Go/No-Go , perception span  and hand reaction time  but not for eye-hand coordination. Pairwise comparisons with the Sidak adjustment showed a significant progressive decrease in the STMLI ratios over time that reached statistical significance at alpha = 0.05 between baseline and final assessment on the Go/No-Go test  perception span  and hand reaction time . These results are summarized in The results indicated multivariate significance for the main effect of time  and 8-column [F = 3.59 p = 0.03] vertical sinusoidal gratings but not for checkerboard patterns. Mauchly's test of sphericity for 16 and 8 column vertical sinusoidal gratings was not significant, so sphericity was assumed and no epsilon (ε) adjustment was used. Pairwise comparisons with the Sidak correction showed that for both stimuli sizes log10-transformed amplitudes after 10 weeks of training were significantly lower than after 5 weeks of training at alpha = 0.05. No other comparisons were significant. After re-running the doubly multivariate analysis of variance on raw, untransformed amplitudes, the main effect of time remained for the 16-column vertical sinusoidal grating but not for the 8-column grating. Again, the P100 amplitude at final assessment  was significantly (p < 0.01) lower than at the intermediate point . No other pairwise comparisons were significant. These results are summarized in Univariate analyses revealed that the multivariate significance for the time effect was significant for log10-transformed amplitudes in response to both 16 [In the present study we hypothesized that administration of OVT oculomotor training protocols before software training may result in larger performance improvements compared to the reverse order due to the initial strengthening of the visual hardware capable of handling greater demands during training of visuomotor integration and information processing skills . Within the design of our study that did not include a control group it is difficult to attribute significant post-training improvements observed in both experimental groups on all but one (contrast sensitivity) Nike/Senaptec measures to the actual effects of training. Since some of the software training drills  directly mimicked test stimuli, it is of no particular surprise that all athletes improved their performance on the Nike/Senaptec measures by the end of their 10 week visual training. It has also been previously reported that improvements on some of the Nike/Senaptec measures can be explained by practice effects within the test-retest paradigm  and 10 weeks  compared to baseline , and not due to changes in theta power. In the hardware-software training group no significant changes in either theta or gamma band activity was observed compared to baseline. Significant training effects observed in both treatment groups as indexed by lower STMLI ratios post-treatment compared to baseline were also primarily related to increases in the 30–40 Hz Fz gamma power for perception span , Go/No-Go , and hand reaction time . Additionally, on the measure of perception span, lower STMLI ratio was also related to a significantly lower Fz 3–7 Hz theta power after 10 weeks of training  compared to baseline .In our previous study using STMLI ratios, we showed that this index is a particularly sensitive measure of neuropsychological status  especially on tasks of visuomotor control that largely depend on the working memory capacity and temporal processing speeds  in our study during the completion of the perception span task is also consistent with proposed theoretical models for the role of theta as well as with empirical evidence. Besides its organizing role in working memory formation as a phase reference for multi-item messages . The finding of reduced P100 latencies to this type of stimulus following visual training of athletes in itself is not novel and is consistent with previous studies. First, several research groups previously showed that athletes participating in dynamic, fast-paced sports  show faster P100 latencies compared to non-athletes in response to similar checkerboard stimuli . This decrease did not depend on the training order. On the surface these results may seem counterintuitive. For example, in clinical populations  administration of vision therapy resulted in increased P100 amplitude suggesting greater activation of the visual cortex that resulted in improved performance on tests of visual attention and visual acuity, respectively  stimulus and not in response to sustained parvocellular stimuli (checkerboard patterns). The magnocellular system may, according to Laycock et al.  may be iThis elegant narrative, however, is somewhat muddled by the absence of the magnocellular advantage in the present study. In fact, on average, participants in both groups were about 13 ms slower in their response to magnocellular (VSG) stimuli than to parvocellular (checkerboard stimuli). Part of the reason may be related to undiagnosed/unreported history of concussion in this group of young ice hockey players. Although we did remove from the analyses the data from the players who had reported a history of concussion, it is very possible that within such a traumatic sport as ice hockey many of the concussions remain undiagnosed and underreported. This would certainly fit with the VEP profile of the athletes in our study, as we previously showed that individuals with a history of concussion had significantly slower response latencies to magnocellular stimuli than those without such history (Poltavski et al., Contrary to our original hypothesis, software training before oculomotor training showed more favorable electrophysiological profiles consistent with more efficient visual processing. Our hypothesis was largely based on the results of a series of studies by the Ciuffreda group that showed that administration of oculomotor vision training emphasizing vergence, accommodation and version to individuals with a history of mTBI resulted not only in significant clinical improvements of their oculomotor deficits (Thiagarajan and Ciuffreda, Indeed, Caldani et al.  recentlyOverall, the results of the present study suggest that our comprehensive training of the oculomotor system in combination with training of the visual information processing skills resulted in significant improvements on most measures of the Sensory Station. More importantly we were able to show the utility of the EEG-derived STMLI ratios to monitor training progress. This index suggested greater efficiency in visual information processing and cognitive resource allocation following 10 weeks of visual training. Similarly, our VEP components of P100 latency and amplitude also suggested improved speeds of visual signal processing at the end of study in combination with more effective and parsimonious cognitive resource allocation and attentional engagement. These electrophysiological indexes in some cases favored the software-hardware training order of procedural administration. This may suggest improved preparedness of the oculomotor system in our youth athletes for administration of targeted protocols of the Optometric Vision Therapy. Future studies with athletes and comprehensive SVT protocols should also include a placebo control group, and should also compare the effectiveness of such training in athletes with a history of concussion. Convenience sampling, age variability, developmental factors and correlational nature of the findings observed in the present study may further limit their generalizability onto athletic populations and, therefore, require further inquiry. Pre- and post-training measures should also include direct measures of athletic performance to evaluate the degree of transfer on the actual performance in the sport of interest. Both EEG and VEP measures used in the present study have considerable potential for future utilization in SVT research and clinical populations.The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.The studies involving human participants were reviewed and approved by the Institutional Review Board of the University of North Dakota. Written informed consent to participate in this study was provided by the participants' legal guardian/next of kin.DP oversaw all aspects of the study including subject recruitment, testing, training, and data collection. He conducted all statistical analyses and wrote up the bulk of the manuscript sections. DB significantly contributed to subject recruitment, testing, data collection, analysis interpretation, and literature review. CP significantly contributed to subject testing and training as well as to the preparation of the materials and procedures sections of the manuscript. All authors contributed to the article and approved the submitted version.This study was funded by the North Dakota Department of Commerce: Research ND Program. Project title: Evaluation of the Effectiveness of Sports Vision Programs in Improving Performance and Health in ND Youth Athletes. Award Dates: 2015–2017. Award # 15-02-G-88.DB was employed by the company Valley Vision Clinic. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.