Single bout of vibration-induced hamstrings fatigue reduces quadriceps inhibition and coactivation of knee muscles after anterior cruciate ligament (ACL) reconstruction

Persistent quadriceps strength deficits in individuals with anterior cruciate ligament reconstruction (ACLr) have been attributed to arthrogenic muscle inhibition (AMI). The purpose of the present study was to investigate the effect of vibration-induced hamstrings fatigue on AMI in patients with ACLr. Eight participants with unilateral ACLr (post-surgery time: M = 46.5, SD = 23.5 months; age: M = 21.4, SD = 1.4 years) and eight individuals with no previous history of knee injury (age: M = 22.5, SD = 2.5 years) were recruited. A fatigue protocol, consisting of 10 min of prolonged local hamstrings vibration, was applied to both the ACLr and control groups. The central activation ratio (CAR) of the quadriceps was measured with a superimposed burst of electrical stimulation, and hamstrings/quadriceps coactivation was assessed using electromyography (EMG) during isometric knee extension exercises, both before and after prolonged local vibration. For the ACLr group, the hamstrings strength, measured by a load cell on a purpose-built chair, was significantly (P = 0.016) reduced about 14.5%, indicating fatigue was actually induced in the hamstrings. At baseline, the ACLr group showed a trend (P = 0.051) toward a lower quadriceps CAR (M = 93.2%, SD = 6.2% versus M = 98.1%, SD = 1.1%) and significantly (P = 0.001) higher hamstrings/quadriceps coactivation (M = 15.1%, SD = 6.2% versus M = 7.5%, SD = 4.0%) during knee extension compared to the control group. The fatigue protocol significantly (P = 0.001) increased quadriceps CAR (from M = 93.2%, SD = 6.2% to M = 97.9%, SD = 2.8%) and significantly (P = 0.006) decreased hamstrings/quadriceps coactivation during knee extension (from M = 15.1%, SD = 6.2% to M = 9.5%, SD = 4.5%) in the ACLr group. In conclusion, vibration-induced hamstrings fatigue can alleviate AMI of the quadriceps in patients with ACLr. This finding has clinical implications in the management of recovery for ACLr patients with quadriceps strength deficits and dysfunction.     

Educational Factors and Financial Implications of Medical Students Choosing and Matching Into Orthopedic Surgery

BackgroundMentorship and research have been shown to be important decision factors influencing medical students to pursue a particular specialty. The cost of applying to orthopedic surgery residency is at an all-time high. The purpose of this study is to identify the factors which increase the likelihood of medical students matching into orthopedic surgery, identify the timing and strength of impact these factors have on medical students’ career choices, determine how many students have chosen orthopedic surgery prior to beginning medical school, and compare the financial impact of applying to orthopedics.Methods608 medical students were surveyed 5 times during medical school (at the start of M1, M2, M3, M4 year and after the match process) to identify ongoing factors that influence their career choice and ultimately matching in orthopedic surgery. Unadjusted odds ratios and cost analysis were used to determine the factors influencing specialty choice. Level of evidence: IIIResultsStudents who matched into orthopedic surgery were more likely to be mentored by an orthopedic surgeon at all 5 survey points (M1 OR=30.93, M2 OR=12.38, M3 OR=17.96, M4 OR=65.2, Match OR=215.45) and involved in orthopedic surgery research at the last 4 survey points (M2 OR=20.05, M3 OR=14.00, M4 OR=12.00, Match OR=1566.60) compared to students who did not match into orthopedic surgery. 10 out of 19 students (52.6%) who matched into orthopedic surgery listed the specialty as their preference in the M1 survey. Students who matched into orthopedic surgery spent $8,838.80 on applications and interviews, while students applied to and matched into other specialties spent an average of $6,173.4 (p-value=0.007).ConclusionMany students have a predetermined plan to enter orthopedic surgery prior to medical school. Mentorship and research are important factors increasing students’ interest in orthopedic surgery and ultimately leading to a successful match process. Going through the orthopedic surgery match process is significantly more expensive than other specialties. Level of Evidence: IV     

Risk of venous thromboembolism among users of third generation oral contraceptives compared with users of oral contraceptives with levonorgestrel before and after 1995: cohort and case-control analysis

ObjectiveTo compare the risk of idiopathic venous thromboembolism among women taking third generation oral contraceptives (with gestodene or desogestrel) with that among women taking oral contraceptives with levonorgestrel.DesignCohort and case-control analyses derived from the General Practice Research Database.SettingUK general practices, January 1993 to December 1999.ParticipantsWomen aged 15-39 taking third generation oral contraceptives or oral contraceptives with levonorgestrel.ResultsThe adjusted estimates of relative risk for venous thromboembolism associated with third generation oral contraceptives compared with oral contraceptives with levonorgestrel was 1.9 (95% confidence interval 1.3 to 2.8) in the cohort analysis and 2.3 (1.3 to 3.9) in the case-control study. The estimates for the two types of oral contraceptives were similar before and after the warning issued by the Committee on Safety of Medicines in October 1995. A shift away from the use of third generation oral contraceptives after the scare was more pronounced among younger women (who have a lower risk of venous thromboembolism) than among older women. Fewer cases of venous thromboembolism occurred in 1996 and later than would have been expected if the use of oral contraceptives had remained unchanged.ConclusionsThese findings are consistent with previously reported studies, which found that compared with oral contraceptives with levonorgestrel, third generation oral contraceptives are associated with around twice the risk of venous thromboembolism.     

Pre‐ and Postsurgery Behavioral Compliance,Patient Health,and Postbariatric Surgical Weight Loss

This study investigated the relationship between weight loss from gastric bypass surgery, patient characteristics, and compliance with physician instructions before and after surgery. A chart review of psychiatric and medical files was conducted for an initial cohort of 172 patients in a postsurgical management program. A total of 112 patients (primarily women (85%), white (79%), and well educated) from this cohort had presurgical data. Of these 112 subjects, 67 (60%) had postsurgical compliance information and BMI at 24 months postsurgery. The relationships between weight loss and a number of demographic, psychiatric, comorbid, and behavioral compliance factors were examined for these 67 patients. Missed appointments and noncompliance with exercise and weight loss plan instructions were high before and after surgery (65% vs. 72% for missed appointments, 39% vs. 51% for exercise, 42% vs. 57% for weight loss instructions). Although poor food choices were not frequently a problem before surgery (11%), they increased significantly after surgery: 37%, χ²(1) = 25.00, P < 0.001. Participants who lost the least weight at 2 years postsurgery were more likely to be nonwhite (r = 0.27, P = 0.039), have a lower socioeconomic status (SES) (r = 0.285, P = 0.02), and have a diagnosis of binge eating before surgery (r = 0.25, P = 0.039). Having more contact with patients and requiring adherence to behavioral changes, especially with respect to exercise and dietary restrictions, may improve the long‐term outcomes for bariatric procedures. In addition, those patients who are depressed and suffer from binge eating may need special attention from physicians during long‐term postoperative follow‐up.     

Oral contraceptives and myocardial infarction: results of the MICA case-control study

ObjectivesTo determine the association between myocardial infarction and use of different types of oral contraception in young women.DesignCommunity based case-control study. Data from interviews and general practice records.SettingEngland, Scotland, and Wales.ParticipantsCases (n=448) were recruited from women aged between 16 and 44 who had suffered an incident myocardial infarction between 1 October 1993 and 16 October 1995. Controls (n=1728) were women without a diagnosis of myocardial infarction matched for age and general practice.ResultsThe adjusted odds ratio for myocardial infarction was 1.40 (95% confidence interval 0.78 to 2.52) for all combined oral contraceptive users, 1.10 (0.52 to 2.30) for second generation users, and 1.96 (0.87 to 4.39) for third generation users. Subgroup analysis by progestagen content did not show any significant difference from 1, and there was no effect of duration of use. The adjusted odds ratio for third generation users versus second generation users was 1.78 (0.66 to 4.83). 87% of cases were not exposed to an oral contraceptive, and 88% had clinical cardiovascular risk factors or were smokers, or both. Smoking was strongly associated with myocardial infarction: adjusted odds ratio 12.5 (7.29 to 21.5) for smoking 20 or more cigarettes a day.ConclusionsThere was no significant association between the use of oral contraceptives and myocardial infarction. The modest and non-significant point estimates for this association have wide confidence intervals. There was no significant difference between second and third generation products.

Key message

• There is no evidence of a difference between second and third generation oral contraceptives on risk of myocardial infarction
• There is no significantly increased risk of myocardial infarction in users of oral contraceptives
• Of women aged under 45 years who suffered a myocardial infarction, 87% were not taking any oral contraceptive
• Of women who suffered myocardial infarction, 88% had one or more known cardiovascular risk factors
• Young women who wish to preserve cardiovascular health should be advised to stop smoking, above all else

     

Automatic exposure control at single- and dual-heartbeat CTCA on a 320-MDCT volume scanner: Effect of heart rate,exposure phase window setting,and reconstruction algorithm

PurposeTo investigate whether electrocardiogram (ECG)-gated single- and dual-heartbeat computed tomography coronary angiography (CTCA) with automatic exposure control (AEC) yields images with uniform image noise at reduced radiation doses.Materials and methodsUsing an anthropomorphic chest CT phantom we performed prospectively ECG-gated single- and dual-heartbeat CTCA on a second-generation 320-multidetector CT volume scanner. The exposure phase window was set at 75%, 70–80%, 40–80%, and 0–100% and the heart rate at 60 or 80 or corr80 bpm; images were reconstructed with filtered back projection (FBP) or iterative reconstruction (IR, adaptive iterative dose reduction 3D). We applied AEC and set the image noise level to 20 or 25 HU. For each technique we determined the image noise and the radiation dose to the phantom center.ResultsWith half-scan reconstruction at 60 bpm, a 70–80% phase window- and a 20-HU standard deviation (SD) setting, the imagenoise level and -variation along the z axis manifested similar curves with FBP and IR. With half-scan reconstruction, the radiation dose to the phantom center with 70–80% phase window was 18.89 and 12.34 mGy for FBP and 4.61 and 3.10 mGy for IR at an SD setting SD of 20 and 25 HU, respectively. At 80 bpm with two-segment reconstruction the dose was approximately twice that of 60 bpm at both SD settings. However, increasing radiation dose at corr80 bpm was suppressed to 1.39 times compared to 60 bpm.ConclusionAEC at ECG-gated single- and dual-heartbeat CTCA controls the image noise at different radiation dose.     

Reproductive biology of the viviparous scorpion,Liocheles australasiae (Fabricius) (Arachnida,Scorpiones, Ischnuridae) III. Structural types and functional phases of the adult ovary

Summary

Five structural types of the adult ovary were distinguished in a parthenogenetic viviparous scorpion Liocheles australasiae based on the presence or absence of swollen ovarian diverticula (SD) containing embryos and/or empty ones (ED) as remnants of past pregnancies. These structural types seem to correspond to the following ovarian functional phases: the ovary (1) with SD and without ED corresponds to the first pregnancy; (2) without SD and with ED to after the first parturition; (3) with SD and ED to the second pregnancy; (4) without SD and with old and new ED to after the second parturition; and (5) with SD and old and new ED to the third pregnancy. Such correspondence indicates that a female can repeat pregnancies at least three times. Some possible cases in which the present structural types correspond to other functional phases were also discussed.     

Influence of premolar extraction or non-extraction orthodontic therapy on the angular changes of mandibular third molars

AimTo compare the angular changes of the third molars relative to the occlusal plane and to the second molar long axis in extraction group and compare these changes with a non extraction group.Materials and methodsThe study included pre and post treatment panoramic radiograph records of 90 subjects treated by first premolar extractions and 90 subjects who had been treated with non extraction orthodontic therapy (n = 90). Two angular variables were measured. Firstly, the angle between the long axis of the third molar and the occlusal plane (M3–OP) and secondly, the angle between the long axis of the third molar and the long axis of the second molar (M3–M2). Data were analyzed by paired and student’s t-test.ResultThe analyzed data to assess the changes in the third molar angulation from pretreatment to post treatment did not vary significantly in both the groups (p < 0.05). Both the groups showed decreased angular values. The M3–OP angular difference was (−7.3 ± 2.45) in extraction group as compared to (−5.85 ± 1.77) in non extraction group. The M3–M2 angular difference of (−4.26 ± 3.11) in extraction group and (−2.98 ± 1.74) in non-extraction group was observed.ConclusionExtraction of premolars did not demonstrate considerable changes on the angulation of the third molars. The factors other than premolar extractions may influence the angulation of the third molars.     

LAMP3 (CD208) Expression in Squamous Cell Carcinoma and Epithelial Dysplasia of the Oral Cavity and Clinicopathological Characteristics of Unfavorable Prognosis

Background:This study aimed to evaluate LAMP3 (CD208) gene expression in oral squamous cell carcinoma (OSCC) and dysplastic oral epithelium by quantitative real-time polymerase chain reaction (qPCR) and compare LAMP3 expression in different disease grades and stages.Methods:In this study, 60 OSCC and dysplastic oral epithelium samples were obtained from the Mashhad University of Medical Sciences together with their demographic and clinicopathological documents. LAMP3 expression was measured by qPCR.Results:LAMP3 expression was significantly greater in OSCC than in dysplasia samples (P=0.001), in grade III OSCC than in grades I and II, and also greater in advanced than in early OSCC disease stage (P=0.001).Conclusion:The significantly greater LAMP3 expression in OSCC than in dysplastic epithelium indicates a role for LAMP3 in carcinogenesis in oral mucosa. Our results suggest LAMP3 may be useful as an anticancer target and/or to predict disease pathogenesis in OSCC patient’s cells.Key Words: Clinicopathological, Grade, Epithelial dysplasia, LAMP3, Stage, Squamous cell carcinoma.     

Do Mechanical Effectiveness and Recipient Species Influence Intentional Signal Laterality in Captive Chimpanzees (<Emphasis Type="Italic">Pan troglodytes</Emphasis>)?

Studying the relationships between the directions of brain lateralization for handedness and language can shed light on mechanisms underlying hemispheric specialization for manipulation and signalling functions. We investigated the influence of manipulation and communication functions and of recipient species (conspecific- versus human-directed communication) on manual laterality in signalling context, taking several factors into account simultaneously. We assessed laterality in 39 chimpanzees (Pan troglodytes), including 4 manipulators (mechanically effective social actions used to get things done) and 18 gestures (mechanically ineffective social actions implying that the signaller takes the recipient’s response into account). We focused on the following factors: interactional context components (e.g., visual fields of both interactants), degree of use of signals (“rare” for signals performed by only a few subjects in the population or “common” for signals performed by many subjects), mechanical effectiveness, subjects’ sociodemographic characteristics (e.g., age and hierarchy), and recipient species. We found a significant population-level right-hand bias for one type of human-directed gesture (slap hand). Mechanical effectiveness influenced laterality: right-hand use was more pronounced for conspecific-directed gestures than for conspecific-directed manipulators. The laterality of conspecific-directed gestures overall did not differ from that of human-directed gestures. However, we found an indirect influence of recipient species on laterality as conspecific- and human-directed gestural lateralities were modulated differently by the position of the recipient in the signaller’s visual field and by signaller’s age. We hypothesize that the communication nature of gestures might have developed from manipulators. Manipulators may have contributed to the emergence and the evolution of the left-lateralized communication system in primates.     

The power requirements (Glossophaginae: Phyllostomidae) in nectar-feeding bats for clinging to flowers

Nectar-feeding bats are the heaviest pollinators exploiting flowers in a hovering foraging mode. As hovering flight is considered to be energetically costly, clinging to flowers would be beneficial from an energetic perspective. I examined the rate of oxygen consumption and carbon dioxide release during clinging flower visitation in two 10-g Glossophaga soricina (Glossophinae: Phyllostomidae) to evaluate the potential energetic benefit of clinging versus hovering. In addition, I measured the duration of flower visits of free-ranging glossophagine bats to Markea neurantha (Solanaceae), a bat-pollinated plant that allows both hovering and clinging flower visitation. After 20 s of clinging to an artificial respiratory mask, the bats respiratory exchange ratio did not significantly deviate from 1, indicating the combustion of sugar. The average oxygen uptake rate equaled 1.39 ml min^–1 (±0.38 SD, STPD) and the carbon dioxide release rate equaled 1.33 ml min^–1 (±0.20 SD, STPD) for feeder visits longer than 20 s (n=79). Converting the oxygen uptake rate into power input yielded 0.49 W, less than a third of the power requirements for hovering for a 10-g bat. Free-ranging 10-g glossophagine bats exploited flowers of M. neurantha for, on average, 0.32 s ( ±0.14 SD, n=273) during hovering and for 0.39 s (±0.18 SD, n=152) during clinging visitations. A comparison between the power requirements of flower exploitation in differently sized bats indicates that clinging would benefit larger nectar-feeding bats to a greater extent than smaller species.Communicated by G. Heldmaier     

Time intervals and patient-level factors in oral cancer diagnostic pathways: An application of the WHO framework in India

BackgroundOral cancer, a leading cancer-site in India, is often detected at advanced stages. We evaluated the time intervals from first symptom to help-seeking and diagnosis among oral cancer patients.MethodologyIn this cross-sectional study, we recruited 226 consecutive oral cancer patients (mean age ( ± SD) 51.9 years ( ± 10.9); 81.9% men; 70.3% advanced stage) registered for diagnosis and treatment, between 2019 and 2021 at a cancer care centre in South India. We used WHO framework and previously standardized tools to record time intervals (appraisal, help-seeking and diagnostic) and baseline characteristics. We utilized multivariable logistic regression models to test the associations between ‘prolonged (i.e., over 1 month) time intervals’) and patient-level factors to estimate odds ratios (ORs) with 95% confidence intervals (CIs).ResultsOver a half of patients presented with prolonged appraisal (60%) and help-seeking intervals (57%), and a third (34%) reported prolonged diagnostic interval. Patients with no formal education, no routine healthcare visits, no self-reported risk factors, and those who did not perceive initial symptoms to be serious were 2–4 times more likely to have prolonged appraisal and help-seeking than the rest. High travel costs and self-decision for visiting healthcare facility prolonged help-seeking. Diagnostic interval was prolonged only among women OR= 2.7 (95% CI: 1.2–6.1)) and in patients whose first doctor’s opinion was ‘nothing to worry’ OR (=7.3 (95% CI: 2.6–20.5)). ‘Correct knowledge of cancer’ shortened appraisal and help-seeking intervals and ‘incorrect knowledge and negative beliefs’ prolonged diagnostic interval.ConclusionOur findings highlight that interventions targeting sociocultural and economic determinants, symptom awareness, sensitizing persons at risk (especially women) and primary care providers might reduce overall time to diagnosis. Further, patients without any known risk factors for oral cancer might be at-risk for prolonged appraisal interval. These might help inform ‘pull’ strategies for cancer control in India and similar settings.     

Pedometer-determined physical activity levels of healthy children and children with Down’s syndrome

Purpose: Children with Down’s syndrome (DS) are considered sedentary and less engaged in recommended physical activity (PA) levels. This study compared the PA levels between children with DS and healthy children in Saudi Arabia.

Methods: The study included 85 children divided into two groups. The DS group comprised 37 children with DS aged 8–12?years recruited from the Down Syndrome Charitable Association and Al-Nahda Schools for DS. The healthy group comprised 41 healthy children aged 8–12?years recruited from regular schools in the same region. PA levels were measured over 7?days using a pedometer.

Results: The healthy group was more active than the DS group (p?p?p?Conclusions: The DS group had a high body mass index and physical inactivity compared with the second group. Obesity and physical inactivity among Saudi Arabian children with and without DS are major health concerns. Therefore, concerted efforts are needed to combat childhood obesity, promote PA, improve patient quality of life, and reduce the sedentary lifestyle among Saudi children and adolescents.     

3D structured illumination microscopy of mammalian embryos and spermatozoa

Background

Super-resolution fluorescence microscopy performed via 3D structured illumination microscopy (3D-SIM) is well established on flat, adherent cells. However, blastomeres of mammalian embryos are non-adherent, round and large. Scanning whole mount mammalian embryos with 3D-SIM is prone to failure due to the movement during scanning and the large distance to the cover glass.

Results

Here we present a highly detailed protocol that allows performing 3D-SIM on blastomeres of mammalian embryos with an image quality comparable to scans in adherent cells. This protocol was successfully tested on mouse, rabbit and cattle embryos and on rabbit spermatozoa.

Conclusions

Our protocol provides detailed instructions on embryo staining, blastomere isolation, blastomere attachment, embedding, correct oil predictions, scanning conditions, and oil correction choices after the first scan. Finally, the most common problems are documented and solutions are suggested. To our knowledge, this protocol presents for the first time a highly detailed and practical way to perform 3D-SIM on mammalian embryos and spermatozoa.

     

Efficacy and safety of propolis mouthwash in management of radiotherapy induced oral mucositis; A randomized,double blind clinical trial

Aim and BackgroundPropolis has been used for the management of oral mucositis in a number of studies. Due to lack of sufficient evidence especially in radiotherapy induced oral mucositis, the present study was designed to evaluate the efficacy and safety of propolis mouthwash in oral mucositis and dysphagia in patients undergoing head and neck radiotherapy.Materials and methodsThis study was a prospective, randomised, double-blind, placebo-controlled trial. The patients randomly divided into two groups receiving either the propolis or the placebo mouthwash. Patients were advised to rinse their mouth with 15 mL three times daily for four weeks. Severity of mucositis and dysphagia were evaluated by the National Cancer Institute Common Toxicity Criteria (NCI-CTC) and Common Terminology Criteria for Adverse Events (CTCAE), respectively.ResultsThirty patients completed the study. Each group consisted of 15 patients. Although, there is not any significant difference between two groups in the first week of radiotherapy, a significant difference was seen in the second, the third and the fourth week (p = 0.03, 0.02, 0.02, respectively). Dysphagia reported as a mild score in the propolis group only in the fourth week which is significant compared with the placebo group (p = 0.01). There is not any serious adverse effect related to propolis or placebo during the study.ConclusionIt seems that propolis mouthwash is an effective and safe medication for alleviation of oral mucositis and dysphagia in patients under head and neck radiotherapy.     

Efficacy of rupatadine in reducing the incidence of dengue haemorrhagic fever in patients with acute dengue: A randomised,double blind,placebo-controlled trial

BackgroundRupatadine was previously shown to reduce endothelial dysfunction in vitro, reduced vascular leak in dengue mouse models and to reduce the extent of pleural effusions and thrombocytopenia in patients with acute dengue. Therefore, we sought to determine the efficacy of rupatadine in reducing the incidence of dengue haemorrhagic fever (DHF) in patients with acute dengue.Methods and findingsA phase 2, randomised, double blind, placebo controlled clinical trial was carried out in patients with acute dengue in Sri Lanka in an outpatient setting. Patients with ≤3 days since the onset of illness were either recruited to the treatment arm of oral rupatadine 40mg for 5 days (n = 123) or the placebo arm (n = 126). Clinical and laboratory features were measured daily to assess development of DHF and other complications. 12 (9.7%) patients developed DHF in the treatment arm compared to 22 (17.5%) who were on the placebo although this was not significant (p = 0.09, relative risk 0.68, 95% CI 0.41 to 1.08). Rupatadine also significantly reduced (p = 0.01) the proportion of patients with platelet counts <50,000 cells/mm³ and significantly reduced (p = 0.04) persisting vomiting, headache and hepatic tenderness (p<0.0001) in patients. There was a significant difference in the duration of illness (p = 0.0002) although the proportion of individuals who required hospital admission in both treatment arms. Only 2 patients on rupatadine and 3 patients on the placebo developed shock, while bleeding manifestations were seen in 6 patients on rupatadine and 7 patients on the placebo.ConclusionsRupatadine appeared to be safe and well tolerated and showed a trend towards a reducing proportion of patients with acute dengue who developed DHF. Its usefulness when used in combination with other treatment modalities should be explored.Trial registrationInternational Clinical Trials Registration Platform: SLCTR/2017/024.     

Crowdsourcing as a Screening Tool to Detect Clinical Features of Glaucomatous Optic Neuropathy from Digital Photography

AimCrowdsourcing is the process of simplifying and outsourcing numerous tasks to many untrained individuals. Our aim was to assess the performance and repeatability of crowdsourcing in the classification of normal and glaucomatous discs from optic disc images.MethodsOptic disc images (N = 127) with pre-determined disease status were selected by consensus agreement from grading experts from a large cohort study. After reading brief illustrative instructions, we requested that knowledge workers (KWs) from a crowdsourcing platform (Amazon MTurk) classified each image as normal or abnormal. Each image was classified 20 times by different KWs. Two study designs were examined to assess the effect of varying KW experience and both study designs were conducted twice for consistency. Performance was assessed by comparing the sensitivity, specificity and area under the receiver operating characteristic curve (AUC).ResultsOverall, 2,540 classifications were received in under 24 hours at minimal cost. The sensitivity ranged between 83–88% across both trials and study designs, however the specificity was poor, ranging between 35–43%. In trial 1, the highest AUC (95%CI) was 0.64(0.62–0.66) and in trial 2 it was 0.63(0.61–0.65). There were no significant differences between study design or trials conducted.ConclusionsCrowdsourcing represents a cost-effective method of image analysis which demonstrates good repeatability and a high sensitivity. Optimisation of variables such as reward schemes, mode of image presentation, expanded response options and incorporation of training modules should be examined to determine their effect on the accuracy and reliability of this technique in retinal image analysis.