Clinical, Radiographic and Gait Parameters Associated with Medial Arch Pain in the Flexible Pediatric Flatfoot.

Pain in the flexible flatfoot is a common complaint, if present it is important to find its exact location and causes Therefore, the study aimed to find differences between children with and without medial arch pain and relate them to the reduction of pain following surgical treatment. Children with idiopathic flexible flatfeet were retrospectively included in the study. All children underwent a clinical, radiographic, and gait examination. The feet were subdivided into 2 groups: asymptomatic and those with medial arch pain. Factors associated with medial arch pain were identified via t test. Significant radiological and gait parameters were correlated to the change in medial arch pain score following surgery. Included were 322 feet belonging to 177 children, with the mean age of 11.8 (SD = 2.2) years. The pain was perceived in 52% of the feet, of these, 74% in the medial arch. In the group with pain, 31 feet received a gait analysis following surgery. The radiological parameters, talus-1 and -2 metatarsal angles and the gait parameter, calcaneal lateral shift during walking showed a significant difference (p ≤ .004) between the no pain and pain groups and were associated (R2 ≥0.14, p ≤ .04) with the reduction in pain following surgery. The increased talus-1 and -2 metatarsal angles and the calcaneal lateral shift may cause increased tension on the soft-tissues along the medial side of the foot and may produce pain. Therapies aiming at improving the medial arch pain should be directed to normalize the talus-1 or -2 metatarsal angles and the calcaneal lateral shift.

[Correction of complex defomities around the Knee Joint]. / Komplexe Achskorrekturen um das Kniegelenk.

Complex deformities around the knee joint are usually severe and have several aetiologies. They can be present in one or more planes, with variations in severity between planes. The occurrence and progression of the deformity can be influenced by local and systemic factors. Several types of osteotomies and fixation methods are available to correct these complex deformities. The selection of the osteotomy used to correct a deformity depends on the type of deformity, its severity and its aetiology. Therefore, precise planning taking into consideration the above factors is necessary to achieve the goal.

Increasing fruit and vegetable intake has no effect on retinal vessel caliber in adults at high risk of developing cardiovascular disease.

BACKGROUND AND AIM: Retinal vessel abnormalities are associated with cardiovascular disease (CVD) risk. To date, there are no trials investigating the effect of dietary factors on the retinal microvasculature. This study examined the dose response effect of fruit and vegetable (FV) intake on retinal vessel caliber in overweight adults at high CVD risk. METHODS AND RESULTS: Following a 4 week washout period, participants were randomized to consume either 2 or 4 or 7 portions of FV daily for 12 weeks. Retinal vessel caliber was measured at baseline and post-intervention. A total of 62 participants completed the study. Self-reported FV intake indicated good compliance with the intervention, with serum concentrations of zeaxanthin and lutein increasing significantly across the groups in a dose-dependent manner (P for trend < 0.05). There were no significant changes in body composition, 24-h ambulatory blood pressure or fasting blood lipid profiles in response to the FV intervention. Increasing age was a significant determinant of wider retinal venules (P = 0.004) whereas baseline systolic blood pressure was a significant determinant of narrower retinal arterioles (P = 0.03). Overall, there was no evidence of any short-term dose-response effect of FV intake on retinal vessel caliber (CRAE (P = 0.92) or CRVE (P = 0.42)). CONCLUSIONS: This study demonstrated no effect of increasing FV intake on retinal vessel caliber in overweight adults at high risk of developing primary CVD. CLINICAL TRIAL REGISTRATION: NCT00874341.

Relevance of instrumented gait analysis in the prediction of the rebound phenomenon after guided growth intervention.

Predictors of rebound after correction of coronal plane deformities using temporary hemiepiphysiodesis (TH) are not well defined. The following research questions were tested: (1) Is the dynamic knee joint load useful to improve rebound prediction accuracy? (2) Does a large initial deformity play a critical role in rebound development? (3) Are BMI and a young age risk factors for rebound? Fifty children and adolescents with idiopathic knee valgus malalignment were included. A deviation of the mechanical femorotibial angle (MFA) of ≥ 3° into valgus between explantation and the one-year follow-up period was chosen to classify a rebound. A rebound was detected in 22 of the 50 patients (44%). Two predictors of rebound were identified: 1. reduced peak lateral knee joint contact force in the first half of the stance phase at the time of explantation (72.7% prediction); 2. minor initial deformity according to the MFA (70.5% prediction). The best prediction (75%) was obtained by including both parameters in the binary logistic regression method. A TH should not be advised in patients with a minor initial deformity of the leg axis. Dynamic knee joint loading using gait analysis and musculoskeletal modeling can be used to determine the optimum time to remove the plates.

Factors associated with serum/plasma concentrations of vitamins A, C, E and carotenoids in older people throughout Europe: the EUREYE study.

PURPOSE: To report on plasma/serum levels of antioxidant vitamin and carotenoids in older adults resident in multiple countries in Europe and examine relationships with potential modifiers. METHODS: Population-based cross-sectional European Eye Study in 7 centres from northern to southern Europe. In total, 4,133 participants aged 65 years or over, collected by random sampling, were recruited. Questionnaires relating to diet, lifestyle and medical history were administered. Non-fasting blood samples were analysed in a single laboratory for vitamins A, C and E and a panel of carotenoids. Associations were analysed by bootstrapped multivariable regression analysis. RESULTS: Centre and season influenced the serum and plasma concentrations of all antioxidant vitamins and carotenoids. Gender, BMI, smoking, age, education, alcohol consumption and supplement use were also significantly associated with some, but not all, of the antioxidant vitamins and carotenoids examined. The proportion of variance explained ranged from 4.8 % for retinol to 25.2 % for zeaxanthin. CONCLUSIONS: In older people, antioxidant vitamin and carotenoid status varies by centre and season, but is also associated with other behavioural and lifestyle variables. Studies aiming to demonstrate an association between antioxidant vitamins and carotenoid status and chronic disease risk should consider these potential confounders.

Characteristic 3D foot motion patterns during gait of patients with Charcot-Marie-Tooth identified by cluster analysis.

BACKGROUND: CMT is a clinically and genetically heterogenous disease with varying degrees of progression. Different foot deformities, gait and movement patterns are observed. In order to achieve an improved, targeted treatment strategy, the participants are divided into characteristic groups using a mathematical cluster analysis based on the data from the three-dimensional foot kinematics during walking. METHODS: Outpatients from age 5-64 years (N = 33 participants, 62 feet) with a proven CMT type 1 (N = 16, 31 feet) or CMT without any further type assignment (N = 17, 31 feet) were retrospectively analyzed. After a standard clinical examination, participants underwent 3D gait analysis using the Oxford Foot Model. To classify the movement patterns, a k-means cluster analysis was calculated based on the principal component analysis (PCA) of the foot kinematics data. Gait parameters, clinical parameters and X-ray data were statistically tested. RESULTS: The cluster analysis divided the gait data of the participants into two groups. Cluster 1 (N = 21 participants, 34 feet) showed increased dorsiflexion of the hindfoot and increased plantarflexion of the forefoot with cavus position in the sagittal plane, a hindfoot inversion and forefoot pronation with hindfoot varus in the frontal plane and in the transversal plane a forefoot adduction. Cluster 2 (N = 17 participants, 28 feet) deviated significantly from the norm mainly in the frontal plane and were characterized by a strong eversion of the hindfoot with a supination in the forefoot. DISCUSSION: Based on the findings, the resultant clusters can be interpreted as cavovarus feet (cluster 1) and pes valgus (cluster 2). The most reliable variables in the 3D gait analysis to classify CMT feet with regard to significance are the ones in the frontal plane. This subdivision of participants goes hand in hand with the various necessary guidelines for orthopedic treatment.

Treatment of spastic varus/ equinovarus foot with split-tendon transfers in cerebral palsy: How does it affect the hindfoot motion?

INTRODUCTION: The flexible spastic varus foot in cerebral palsy is commonly corrected by split-tendon transfer of tibialis anterior or tibialis posterior. These tendon transfers are said to preserve hindfoot motion, which is until now not been proven. Therefore, the aim of the study was to show the hindfoot motion following split-tendon transfer in comparison to a midtarsal arthrodesis. MATERIALS AND METHODS: A retrospective study was done on patients with flexible spastic varus foot in cerebral palsy who underwent a combined split-tendon transfer of tibialis anterior and posterior. Patients with a rigid foot deformity underwent a midfoot arthrodesis. These children and normal children served as controls. An instrumented gait analysis was done in all patients before and at follow-up. A statistical analysis was done using 2-factor ANOVA with repeated measures on time. RESULTS: Thirteen children underwent a combined split-tendon transfers of tibialis anterior and posterior muscles and 14 children midtarsal arthrodesis. The mean follow-up was 2.4 (SD=0.8) years for flexible varus foot and 1.9 (SD=0.7) years for rigid foot deformity. The preoperative hindfoot range of motion in eversion-inversion was 54% and 49% of TD controls in flexible varus foot and rigid foot deformity respectively. At follow-up, it reduced further to 45% and 42% of TD controls in the respective groups. CONCLUSION: Both flexible and rigid hindfoot deformity reduced the hindfoot motion. However following surgery, the hindfoot motion reduced further and was identical in both groups independent of the type of surgery. This indicates a tenodesis-effect of split-tendon transfers on the hindfoot.

Aflibercept in clinical practice; visual acuity, injection numbers and adherence to treatment, for diabetic macular oedema in 21 UK hospitals over 3 years.

INTRODUCTION: Randomised controlled trials provide evidence that a treatment works. Real world evidence is required to assess if proven treatments are effective in practice. METHOD: Retrospective data collection on patients given aflibercept for diabetic macular oedema over 3 years from 21 UK hospitals: visual acuity (VA); Index of multiple deprivation score (IMD); injection numbers; protocols used, compared as a cohort and between sites. RESULTS: Complete data: 1742 patients (from 2196 eligible) at 1 year, 860 (from 1270) at 2, 305 (from 506) at 3 years. The median VA improved from 65 to 71, 70, 70 (ETDRS letters) at 1, 2 and 3 years with 6, 9 and 12 injections, respectively. Loss to follow-up: 10% 1 year, 28.8% at 3. Centres varied: baseline: mean age 61-71 years (p < 0.0001); mean IMD score 15-37 (p < 0.0001); mean VA 49-68 (p < 0.0001). Only four centres provided a loading course of five injections at monthly intervals and one 6. This did not alter VA outcome at 1 year. Higher IMD was associated with younger age (p = 0.0023) and worse VA at baseline (p < 0.0001) not total number of injections or change in VA. Lower starting VA, higher IMD and older age were associated with lower adherence (p = 0.0010). CONCLUSIONS: The data showed significant variation between treatment centres for starting age, VA and IMD which influenced adherence and chances of good VA. Once treatment was started IMD did not alter likelihood of improvement. Loading dose intensity did not alter outcome at one year.

Prefabricated ankle-foot orthoses for children with cerebral palsy to overcome spastic drop-foot: does orthotic ankle stiffness matter?

BACKGROUND: Spastic drop-foot is a common problem in children with cerebral palsy that may lead to tripping and falling. To improve ankle dorsiflexion in swing phase, prefabricated carbon-composite ankle-foot orthoses are commonly prescribed; by increasing ankle stiffness, these orthoses may also improve knee extension in stance. OBJECTIVES: To compare the effect of a stiff vs. flexible prefabricated ankle-foot orthosis on sagittal plane ankle and knee kinematics and kinetics during walking. STUDY DESIGN: Cross-sectional, repeated-measures, interventional study. METHODS: Twenty-seven children and adolescents with cerebral palsy who had drop-foot in swing were included. Gait analysis was conducted under four conditions: barefoot, shod, with a stiff, and with a flexible orthosis. Participants were divided into two groups including children and adolescents who have a flexed knee during stance (KF, N = 12) and without flexed knee during stance (KE, N = 15). RESULTS: Ankle dorsiflexion in swing phase was significantly improved compared with the shod condition by 6.3 degrees (SD = 3.3 degrees) only in the KE group when using the flexible orthosis. For the stiff orthosis, knee extension in stance was significantly increased by 2.4 degrees (SD = 3.3 degrees) in the KE group compared with the shod condition. No significant improvements were observed for the KF group. Further analysis indicated that only seven patients in the KF group with weak ankle plantarflexors improved knee extension while using the stiff orthosis. CONCLUSIONS: Our results suggested that in the KE group, the flexible orthosis was best suited for patients with drop-foot without a knee extension deficit. The stiff orthosis was not suitable in this group as it caused a hyperextended knee without improving dorsiflexion in swing phase. Therefore, stiffness should be considered when prefabricated orthoses are prescribed.

Is shortening of Tibialis Anterior in addition to calf muscle lengthening required to improve the active dorsal extension of the ankle joint in patients with Cerebral Palsy?

INTRODUCTION: Shortening of the tibialis anterior tendon (TATS) has been shown to improve the ankle dorsiflexion in swing following the calf muscle lengthening procedure (CMLP) in patients with cerebral palsy (CP). Others have reported the similar improvements following CMLP but without TATS. However there are no studies comparing both procedures. Therefore the purpose of the study was to compare the ankle dorsiflexion in swing and foot position in the sagittal plane during gait following TATS and CMLP to that of CMLP alone. MATERIALS AND METHODS: A retrospective study was carried out in CP patients who presented with fixed equinus deformity. They were grouped into unilateral CP and bilateral CP. Depending on the procedures, each group was again subdivided into subgroup CMLP only and subgroup CMLP and TATS (CMLPTATS). All patients were subjected to pre and postoperative clinical and gait analysis. RESULTS: 44 feet in 44 patients were included in the study. Of these, 24 feet (24 patients) belonged to unilateral and 20 feet (20 patients) to bilateral CP group. The mean age of the patients at surgery was 11.5 years (6.0 - 29.0) in the unilateral CP group and 10.5 years (5.0-34.0) in the bilateral CP group. In the unilateral CP group, 12 feet belonged to subgroup CMLP and 12 to subgroup CMLPTATS with a mean equinus contracture of 7.5° in both subgroups. In bilateral CP group, 11 feet belonged to subgroup CMLP with a mean equinus contracture of 5° and 9 to subgroup CMLPTATS, with a mean equinus contracture of 10°. The subgroups did not vary significantly in the demographics, anthropometry, kinematics and kinetics of ankle joint preoperatively. The mean follow up time was 19.7 months. The surgery produced significant changes in both groups and subgroups. However, none of the relevant gait parameters were significantly different between groups and subgroups. SIGNIFICANCE: Adding TATS to CMLP, compared to CMLP alone did not improve ankle dorsiflexion in swing and the foot position more than CMLP alone.

Effects of idiopathic flatfoot deformity on knee adduction moments during walking.

INTRODUCTION: Flatfoot deformity is commonly characterized by a subtalar valgus, a low medial longitudinal arch, and abduction of the forefoot. Although flatfoot deformity has been associated with lower first (KAM1) and second (KAM2) peak knee adduction moments during walking, the biomechanical connection remains unknown. RESEARCH QUESTION: We hypothesized that hindfoot eversion, lateral calcaneal shift correlate with KAM1 and forefoot abduction and arch height with KAM2, due to the lateralization of the ground reaction force vector resulting from shifted heel and forefoot in flatfoot deformity. METHODS: Gait data from 103 children with flatfoot deformity who underwent three-dimensional gait analysis with the Oxford Foot Model were retrospectively included. Children with knee varus/valgus, in- and out-toeing were excluded. Fifteen healthy children with a rectus foot type were also collected from the database. Lateral calcaneal shift was defined as the distance between the projection of the ankle joint center onto the calcaneal axis and the midpoint of the calcaneal axis formed by the medial and lateral calcaneal markers. A subgroup of children with idiopathic flatfoot deformity that had received corrective surgery was also identified. Statistical analysis included Pearson's correlations and independent and paired t-tests (α < .05). RESULTS: When compared to a norm cohort, flatfooted children had significant lower KAM1 and KAM2 (t-test, P < .001). Lateral calcaneal shift correlated with KAM1 and KAM2 (r = 0.42, p < .001 and r = 0.32, P < .001, respectively). Arch height correlated with KAM2 (r = 0.23, p = 0.017). KAM1 and KAM2 normalized after surgery and the change in KAM1 correlated with the change in lateral calcaneal shift for children who underwent corrective surgery. SIGNIFICANCE: Lateral calcaneal shift explains the reduction of KAM1 by lateralization of the point of force application in flatfooted children. It is recommended to consider the lateral calcaneal shift when investigating KAM in gait analysis research.

The Ability to Run in Young People with Cerebral Palsy before and after Single Event Multi-Level Surgery.

The objective of the study is to identify and evaluate possible factors that influence the ability to run before and after single event multi-level surgery (SEMLS). Young patients (6-25 years) with spastic cerebral palsy (GMFCSI-II) were retrospectively included. Type and number of surgical procedures, time for recovery and 3D gait analysis variables were analyzed with respect to the ability to run. In total, 98 patients (38 females; 60 males) who received SEMLS (12 years, SD 3.4) were included and compared to a control group of 71 conservatively treated patients. Of 60 runners pre-surgery, 17 (28%) lost the ability, while gained in 8 of 38 (21%) non-runners. The number of surgical procedures was a significant predictor and those who lost their ability to run had significantly more (mean = 5.9, SD = 1.7), compared to the patients who gained the ability (mean = 3.5, SD = 0.9). Further, pre-surgical function (e.g., gait speed) was significantly different (p < 0.001). Pre-surgical function and the number of surgical procedures seem to play an important role for the gain or loss of the ability to run after surgery. Caution is warranted in patients with lower pre-surgical function and the ability to run, as they seem at a higher risk to lose the ability.

Dynamic stability in cerebral palsy during walking and running: Predictors and regulation strategies.

BACKGROUND: The postural control in cerebral palsy (CP) is often deficient and manifests in a variety of impairments. Consequently, maintaining balance and controlling posture is impeded and results in an increased cost of locomotion and higher risk of falls. The margin of stability is an established measure to quantify dynamic stability during gait. It can be facilitated to analyze impaired control mechanisms, but it is unknown if and how people with CP manage to control the margin of stability during a more demanding motor task, such as running. RESEARCH QUESTION: How do people with cerebral palsy regulate dynamic stability during walking and running? METHODS: Children and adolescents with bilateral cerebral palsy (N = 117; 50 female, 67 male; age 11.0 ± 3.2) were retrospectively included. All underwent instrumented 3D gait analysis, walking and running barefoot at a self-selected gait speed. People with CP were compared to a control group of N = 25 typically developed (TD). Repeated measures ANOVAs were computed to analyze group differences and multiple linear regressions to identify predictors for the medio-lateral margin of stability. RESULTS: The medio-lateral margin of stability was significantly higher in the CP group and was statistically unchanged during running. Different adaptions when running were particularly observed in the lateral trunk lean and step width, which remained high in CP, whereas the TD increased the trunk lean and reduced their step width. Step width was the main predictor for the medio-lateral margin of stability in both gait conditions. SIGNIFICANCE: Young people with cerebral palsy manage to maintain their medio-lateral margin of stability during walking and running, however, with significantly higher safety margins compared to typically developed. This conservative strategy may reflect an adaption to motor and postural control impairments.

Does an overcorrected clubfoot caused by surgery or by the Ponseti method behave differently?

BACKGROUND: Overcorrection is a recognized problem following surgical treatment of congenital clubfoot. Recently this complication has also been mentioned following Ponseti treatment. RESEARCH QUESTION: Do overcorrected clubfeet (OCCF) caused by surgery behave differently from those caused by Ponseti treatment in terms of segmental motion of the feet and show differences in the severity of deformity on X-rays? METHODS: Children between 7 and 12 years with OCCF were included in this study. Depending on the aetiology causing them, the feet were divided into 2 groups (Ponseti and peritalar release surgery). 25 typically developing children served as controls. All subjects were subjected to clinical and radiological examination and 3-Dimensional gait analysis using the Oxford Foot Model. RESULTS: Thirty-two children with OCCF, of these 18 feet in the surgical and 14 feet in the Ponseti group, were included in the study. No radiological differences were seen in the flatfoot parameters between OCCF groups except in the calcaneal inclination angle that was more pathological in the Ponseti group. The clinical ankle plantar flexion was significantly reduced in the surgical group. During walking the range motion of the hindfoot in the frontal plane was significantly reduced in surgically treated feet compared to the Ponseti group. The other parameters did not show any significant difference between groups. SIGNIFICANCE: The overcorrected clubfeet following surgery and Ponseti showed similar appearance and showed no significant differences in 11/12 radiological parameters. The segmental motion of the feet showed no significant differences between groups except the in the range of motion of the subtalar eversion. A considerable subtalar joint motion was present even in the surgical group. These findings might help plan the treatment of these feet.

Compensatory mechanisms in children with idiopathic lower extremity internal rotational malalignment during walking and running.

BACKGROUND: Noticeable in-toeing gait is present in most children with internal rotational malalignment and often a reason to consult an orthopedic specialist. The risk of tripping may be higher for these patients. RESEARCH QUESTION: The aim of this study was to determine compensatory mechanisms adopted by children with internal rotational deformities to avoid tripping and falling during walking and running. METHODS: Sixty-nine patients between 5-18 years with idiopathic internal rotational malalignment were retrospectively included and subdivided into three groups: 18 patients with internal tibial torsion (ITT), 25 patients with internal femoral torsion (ITF) and 26 patients with both (ITB). Twenty-two typically developing age-matched children (TD) were analyzed for comparison. Three-dimensional gait data were evaluated. ANOVA's on two factors, group (ITT, ITF, ITB, TD) and movement (walking, running) with post-hoc t-tests were used to identify significant differences between groups. RESULTS: All groups had significantly greater step width than TD during walking (P ≤ .002) and all torsional groups had significantly greater step width during running (P ≤ .001). Similarly, all torsional groups showed greater peak ankle dorsiflexion in swing during running than TD (P ≤ .006). Only the ITT group showed significantly greater external hip rotation than TD. When compared to TD, the ITF and ITB group had a significantly lower hip abduction moment in stance during running, but not for walking (P ≤ .032). SIGNIFICANCE: Compensatory mechanisms in children with internal rotational deformities were mostly dependent on the location of rotational malalignment. All children with internal rotational malalignment had greater ankle dorsiflexion and greater step width during running. Especially in active patients, this greater ankle dorsiflexion during running may result in overuse of the ankle dorsiflexor muscles, while greater step width may have beneficial effects in normalizing knee adduction moments.

Excessive Lateral Trunk Lean in Patients With Cerebral Palsy: Is It Based on a Kinematic Compensatory Mechanism?

Introduction: Excessive lateral trunk lean is a commonly observed gait deviation in children with cerebral palsy (CP), with implications for energy expenditure and the development of back pain. While the trunk lean toward the stance leg is widely interpreted as a compensatory strategy to unload the hip, in CP the relation to hip abductor muscle strength is only weak. Therefore, other mechanisms may play a role in the prevalence of excessive trunk lean in CP, or it could be a primary motor function deficit. Research Question: Is the excessive lateral trunk lean in patients with CP part of an underlying biomechanical mechanism? Materials and Methods: Patients with bilateral CP (N = 255; age 13.6 ± 6.6 years) were retrospectively included and divided into a group with (n = 174) and without (n = 81) excessive lateral trunk lean. Ten lower-extremity joint angle waveforms were analyzed using a principal component analysis (PCA) to identify patterns of correlated deviations from average angle waveforms. Binary logistic regressions were performed to determine the discriminative capacity of the identified patterns. Results: The PCA identified correlated kinematic patterns, with lower-order patterns showing more common gait pathologies, such as torsional malalignments and crouch gait pattern. Within five patterns, significant (p < 0.0025) group differences were identified. Interestingly, the trunk lean was not always distinctive in these patterns and despite the significant differences their effect sizes were small. The logistic regression was unable to reliably classify patients based on their trunk lean patterns. Discussion: The current study identified multiple trunk lean-related patterns, however, excessive trunk lean was not attributable to a distinctive CP related gait pathology or to a specific compensatory strategy. Overall, the results do not support the hypothesis that excessive trunk lean is part of a biomechanical mechanism. Therefore, it seems more likely that excessive lateral trunk lean is based on other disease specific dysfunctions, influenced by the severity of the disease.

A preliminary model-based assessment of the cost-utility of a screening programme for early age-related macular degeneration.

OBJECTIVES: To estimate the cost-effectiveness of screening for age-related macular degeneration (AMD) by developing a decision analytic model that incorporated and assessed all of the National Screening Committee criteria. A further objective was to identify the major areas of uncertainty in the model, and so inform future research priorities in this disease area. DATA SOURCES: Major databases were searched in March 2004 and updated in January 2005. REVIEW METHODS: Systematic literature reviews covered the epidemiology and natural history of AMD, the screening and treatment effectiveness and health-related quality of life relating to AMD. A hybrid cohort-individual sampling model was implemented to describe the range of pathways between the incidence of age-related maculopathy (ARM) and death via clinical presentation and treatment at different stages of the disease. As significant shortfalls in the data available from the literature were apparent, so a range of primary data sources were also used to populate the model. To obtain estimates for the value of parameters deemed to be within an expert's remit, data describing some parameters were elicited from relevant experts. The data identified informed probability distributions describing the uncertainty around the model parameters. To incorporate joint parameter uncertainty (i.e. correlations between parameters), the AMD natural history model was calibrated probabilistically. Randomly sampled sets of input parameters were assigned weights representing the accuracy of their predictions of a set of observed model outputs. The analysis of the AMD screening model estimated the costs, numbers of quality-adjusted life-years (QALYs) and cases of blindness in a general population sample of 50-year-olds over the remainder of their lifetime, for 16 alternative screening options (including no screening). The reference case analysis incorporated current treatment options of laser photocoagulation and photodynamic therapy. Sensitivity analyses describing six alternative sets of intervention strategies, based on horizon scanning of potential future treatments for AMD, were also undertaken. RESULTS: There remains significant uncertainty about whether any form of screening for AMD is cost-effective. However, annual screening from age 60 years seems to provide the highest mean net benefits, but this is based on a cost-effectiveness estimate that has very poor precision (high levels of uncertainty). The probabilistic sensitivity analysis shows that the 95% credible interval for annual screening from age 60 years ranges from this option dominating the previous option to an incremental cost per QALY of over 0.5 million pounds sterling. Plotting a cost-effectiveness acceptability frontier shows that although annual screening from age 60 years has the highest net benefits at a value of QALY of 30,000 pounds sterling, the associated probability of this option being the most cost-effective option is only around 20%. The sensitivity analyses around potential future treatment options indicate that screening may become more cost-effective with the new treatments. CONCLUSIONS: The conclusions focus on the interpretation of the results from the perspective of defining the major areas of uncertainty, which were defined as disease progression, rates of clinical presentation, screening test and optician effectiveness, treatment effectiveness, and costs of blindness. Future research may be best targeted at assessing how routine data may be used to describe clinical presentation rates of ARM. Other potential studies include a pilot study of the effectiveness of screening and opticians' referral patterns for AMD and a costing study of blindness as a continuum of association with deterioration in vision.

An overview of the clinical applications of optical coherence tomography angiography.

Optical coherence tomography angiography (OCTA) has emerged as a novel, non-invasive imaging modality that allows the detailed study of flow within the vascular structures of the eye. Compared to conventional dye angiography, OCTA can produce more detailed, higher resolution images of the vasculature without the added risk of dye injection. In our review, we discuss the advantages and disadvantages of this new technology in comparison to conventional dye angiography. We provide an overview of the current OCTA technology available, compare the various commercial OCTA machines technical specifications and discuss some future software improvements. An approach to the interpretation of OCTA images by correlating images to other multimodal imaging with attention to identifying potential artefacts will be outlined and may be useful to ophthalmologists, particularly those who are currently still unfamiliar with this new technology. This review is based on a search of peer-reviewed published papers relevant to OCTA according to our current knowledge, up to January 2017, available on the PubMed database. Currently, many of the published studies have focused on OCTA imaging of the retina, in particular, the use of OCTA in the diagnosis and management of common retinal diseases such as age-related macular degeneration and retinal vascular diseases. In addition, we describe clinical applications for OCTA imaging in inflammatory diseases, optic nerve diseases and anterior segment diseases. This review is based on both the current literature and the clinical experience of our individual authors, with an emphasis on the clinical applications of this imaging technology.

Cigarette smoking and age-related macular degeneration in the EUREYE Study.

OBJECTIVE: To examine the association between cigarette smoking and age-related maculopathy (ARM) including age-related macular degeneration (AMD) in the European population. DESIGN: Cross-sectional study. PARTICIPANTS: Four thousand seven hundred fifty randomly sampled > or =65-year-olds from 7 study centers across Europe (Norway, Estonia, United Kingdom, France, Italy, Greece, and Spain). METHODS: Participants underwent an eye examination and digital retinal photography. The images were graded at a single center. Smoking history was ascertained by a structured questionnaire administered by trained fieldworkers. Multinomial and binary logistic regressions were used to examine the association between smoking history and ARM grade and type of AMD, taking account of potential confounders and the multicenter study design. MAIN OUTCOME MEASURES: Photographic images were graded according to the International Classification System for ARM and stratified using the Rotterdam staging system into 5 exclusive stages (ARM 0-3 and ARM 4, also known as AMD). Age-related macular degeneration also was classified as neovascular AMD or geographic atrophy (GA). RESULTS: One hundred fifty-eight cases were categorized as AMD (109 neovascular AMD and 49 GA); 2260 had no signs of ARM (ARM 0). Current smokers had increased odds of neovascular AMD (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.4-4.8) or GA (OR, 4.8; 95% CI, 2.1-11.1), whereas for ex-smokers the odds were around 1.7. Compared with people with unilateral AMD, those with bilateral AMD were more likely to have a history of heavy smoking in the previous 25 years (OR, 5.1; 95% CI, 1.3-20.0). The attributable fraction for AMD due to smoking was 27% (95% CI, 19%-33%). There was no consistent association with ARM grades 1 to 3 and smoking. CONCLUSIONS: These findings highlight the need for increasing public awareness of the risks associated with smoking and the benefit of quitting smoking. Patients with unilateral disease who are current smokers should be advised of the risk of second-eye disease.