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PURPOSE: To determine the outcomes and predisposing factors of Descemet's membrane endothelial keratoplasty (DMEK) complicated by intraoperative fibrinous reaction. METHODS: Retrospective cohort study of 346 DMEKs. Medical charts were reviewed for recipient demographics, surgical indications, donor characteristics, and potential predisposing ocular and systemic factors. For DMEKs complicated by fibrin, surgeons' notes on events leading to fibrin formation and on its intraoperative management, occurrence of graft detachment, primary failure, re-bubbling or regrafting, time to graft clearing, and endothelial cell density were additionally collected. RESULTS: Fifteen (4.3%) DMEKs were complicated by fibrin, which interfered with and protracted graft unfolding in all cases. Median surgical time was longer than for uncomplicated DMEKs (p = 0.001). Graft positioning at the end of surgery was suboptimal in seven eyes (47%) and failed in three (20%). Re-bubbling, primary failure, and regraft rates were of 40%, 33% and 53%, respectively. The corneas that cleared did so in three to eight weeks, with median endothelial cell loss of 53% at 12 months. Use of anticoagulants was a preoperative risk factor (p = 0.01). Surgeon-identified intraoperative factors included beginner surgeons (87%), prolonged AC shallowing (47%) and graft manipulations (33%), intraocular bleeding (27%), new injector (20%), tight donor scroll (13%), and floppy iris (13%). CONCLUSION: Fibrinous reaction is a rare intraoperative complication of DMEK that interferes with graft unfolding and results in poor outcomes. Anticoagulant use appears to be a risk factor and may be compounded by surgical trauma to vascular tissues and prolonged surgical maneuvers.

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OBJECTIVE: To investigate how dacryoscintigraphy (DSG) may benefit surgical planning for functional epiphora. METHODS: A retrospective multicenter case series was performed on patients with symptomatic tearing despite no identified external cause and normal lacrimal probing and irrigation (i.e., functional epiphora). All patients had preoperative DSG testing. Patients were excluded if DSG testing failed to detect a tear flow abnormality. Those with delayed tear flow prior to entering the lacrimal sac (presac) on DSG underwent surgery aimed at improving flow into the lacrimal sac. Those with delayed tear flow after the lacrimal sac (postsac) on DSG underwent dacryocystorhinostomy. Surgical success was defined as epiphora being completely resolved, significantly improved, or partially improved. Surgical failure was defined as epiphora being unchanged or worse than at the preoperative timepoint. RESULTS: A total of 77 cases (53 patients) of DSG-guided surgery were included. A presac delay was observed in 14 cases (18.2%) and post-sac delay in 63 (81.8%). Overall surgical success was 83.1% across the cohort. Success was 100% in the presac group and 79.4% in the postsac group (p = 0.06). Mean follow-up time was 22 months (SD = 21 months). CONCLUSION: A role was demonstrated for DSG in the planning of surgery for patients with functional epiphora. The DSG-guided approach, when compared with empirical lacrimal intubation or dacryocystorhinostomy, may be especially useful in cases of functional epiphora that are presac in nature.

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BACKGROUND: Medical students need to acquire a continuously growing body of knowledge during their training and throughout their practice. Medical training programs should aim to provide students with the skills to manage this knowledge. Mobile technology, for example, could be a strategy used through training and practice. The objective of this study was to identify drivers of using mobile technology (an iPad) in a UGME preclinical settings and to study the evolution of those drivers over time. METHODS: We solicited all students from two cohorts of a preclinical component of a Canadian UGME program. They were asked to answer two online surveys: one on their first year of study and another on the second year. Surveys were built based on the Technology Acceptance Model (TAM) to which other factors were also added. Data from the two cohorts were combined and analysed with partial least squares structural equation modelling (PLS-SEM) to test two measurement models, one for each year. RESULTS: We tested fifteen hypotheses on both data sets (first year and second year). Factors that explained the use of an iPad the first year were knowledge, preferences, perceived usefulness and anticipation. In the second year, perceived usefulness, knowledge and satisfaction explained the use of an iPad. Other factors have also significantly, but indirectly influenced the use of the iPad. CONCLUSIONS: We identified factors that influenced the use of an iPad in a preclinical medical program. These factors differed from the first year to the second year in the program. Our results suggest that interventions should be tailored for different point in time to foster the use of an iPad. Further study should investigate how interventions based on these factors may influence implementation of mobile technology to help students acquire ability to navigate efficiently through medical knowledge.

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PURPOSE: To develop and validate neural network (NN) vs logistic regression (LR) diagnostic prediction models in patients with suspected giant cell arteritis (GCA). Design: Multicenter retrospective chart review. METHODS: An audit of consecutive patients undergoing temporal artery biopsy (TABx) for suspected GCA was conducted at 14 international medical centers. The outcome variable was biopsy-proven GCA. The predictor variables were age, gender, headache, clinical temporal artery abnormality, jaw claudication, vision loss, diplopia, erythrocyte sedimentation rate, C-reactive protein, and platelet level. The data were divided into three groups to train, validate, and test the models. The NN model with the lowest false-negative rate was chosen. Internal and external validations were performed. RESULTS: Of 1,833 patients who underwent TABx, there was complete information on 1,201 patients, 300 (25%) of whom had a positive TABx. On multivariable LR age, platelets, jaw claudication, vision loss, log C-reactive protein, log erythrocyte sedimentation rate, headache, and clinical temporal artery abnormality were statistically significant predictors of a positive TABx (P≤0.05). The area under the receiver operating characteristic curve/Hosmer-Lemeshow P for LR was 0.867 (95% CI, 0.794, 0.917)/0.119 vs NN 0.860 (95% CI, 0.786, 0.911)/0.805, with no statistically significant difference of the area under the curves (P=0.316). The misclassification rate/false-negative rate of LR was 20.6%/47.5% vs 18.1%/30.5% for NN. Missing data analysis did not change the results. CONCLUSION: Statistical models can aid in the triage of patients with suspected GCA. Misclassification remains a concern, but cutoff values for 95% and 99% sensitivities are provided (https://goo.gl/THCnuU).

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BACKGROUND: Digital inclinometer applications using data from embedded sensors on smartphone/multi-purpose pocket computers or "smart digital inclinometers" (SDIs) are now used to clinically assess range of motion (ROM). OBJECTIVES: The objectives of this study were to assess, compared with a biomechanical gold standard (GS), the trueness and minimal detectable change (MDC) of shoulder range of motion (SROM) measurements obtained from an SDI. METHODS: Twenty-five (n = 25) asymptomatic healthy participants performed three trials of shoulder flexion (SF), shoulder abduction (SA), and shoulder external rotation (SER) at full-range and mid-range. MAIN OUTCOME MEASURES: SROM was measured concurrently from sensor data (pitch, yaw, roll angles) from an iPod Touch installed on the posterior aspect of the humerus and 3D orientation of the upper arm obtained from an optical motion tracking system GS. RESULTS: The mean level of bias between SDI and the GS across all SROM measurements was 3.4°, with a 95% confidence interval varying between -8.9° and 15.8°. The mean and standard deviation absolute difference of SDI measurements with the GS were 5.8° ± 3.7° for SF, 8.7° ± 5.2° for SA, and 1.7° ± 1.4° for SER. The trueness of these values varied according to the movement. MDC was 1.9° for SF, 2° for SA, and 0.3° for SER. CONCLUSIONS: SROM measures in SER with an SDI seem to be accurate and robust for clinical use. However, SROM measures in other planes of motion should be interpreted with caution depending on the evaluation objective, the plane of motion assessed, and the range of ROM measured.

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