128 research outputs found

    Capturing the Occult Central Retinal Artery Occlusion Using Optical Coherence Tomography

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    AIMS: To report spectral-domain optical coherence tomography (OCT) findings in cases of impending or occult central retinal artery occlusion (CRAO) in which a diagnosis other than CRAO was made on initial presentation. METHODS: Retrospective, observational case series of patients diagnosed with CRAO for whom on initial presentation fundal examination and OCT findings were deemed unremarkable and/or a diagnosis other than CRAO was made. OCT images from the initial presentation were then reviewed for evidence of inner retinal ischaemia. RESULTS: In total, 214 cases of CRAO were identified. Eleven patients (5.14%) had been given an alternative initial diagnosis at their first presentation in casualty and were included. The age range was 20–84 years and 81% (9/11) were male. On review of initial OCT imaging performed in casualty, all cases had evidence of inner retinal ischaemia. Conclusions: CRAO is an ophthalmic emergency which leads to vision loss which is often irreversible. Examination of the fundus may be normal early in the course of the disease and therefore a timely diagnosis may be missed. This case series reports the OCT findings of inner retinal ischaemia in patients with occult or impending CRAO which may aid in the early diagnosis and referral to stroke services

    Computer analysis of individual cataract surgery segments in the operating room

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    Purpose: Objective feedback is important for the continuous development of surgical skills. Motion tracking, which has previously been validated across an entire cataract procedure, can be a useful adjunct. We aimed to measure quantitative differences between junior and senior surgeons’ performance in three distinct segments. We further explored whether automated analysis of trainee surgical videos through PhacoTracking could be aligned with metrics from the EyeSi virtual reality simulator, allowing focused improvement of these areas in a controlled environment. / Methods: Prospective cohort analysis, comparing junior vs. senior surgeons’ real-life performance in distinct segments of cataract surgery: continuous curvilinear capsulorhexis (CCC), phacoemulsification, and irrigation and aspiration (I&A). EyeSi metrics that could be aligned with motion tracking parameters were identified. Motion tracking parameters (instrument path length, number of movements and total time) were measured. t-test used between the two cohorts for each component to check for any significance (p < 0.05). / Results: A total of 120 segments from videos of 20 junior and 20 senior surgeons were analysed. Significant differences between junior and senior surgeons were found during CCC (path length p = 0.0004; number of movements p < 0.0001; time taken p < 0.0001), phacoemulsification (path length p < 0.0001; number of movements p < 0.0001; time taken p < 0.0001), and irrigation and aspiration (path length p = 0.006; number of movements p = 0.013; time taken p = 0.036). / Conclusion: Individual segments of cataract surgery analysed using motion tracking appear to discriminate between junior and senior surgeons. Alignment of motion tracking and EyeSi parameters could enable independent, task specific, objective and quantitative feedback for each segment of surgery thus mirroring the widely utilised modular training

    Development and international validation of custom-engineered and code-free deep-learning models for detection of plus disease in retinopathy of prematurity: a retrospective study.

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    BACKGROUND: Retinopathy of prematurity (ROP), a leading cause of childhood blindness, is diagnosed through interval screening by paediatric ophthalmologists. However, improved survival of premature neonates coupled with a scarcity of available experts has raised concerns about the sustainability of this approach. We aimed to develop bespoke and code-free deep learning-based classifiers for plus disease, a hallmark of ROP, in an ethnically diverse population in London, UK, and externally validate them in ethnically, geographically, and socioeconomically diverse populations in four countries and three continents. Code-free deep learning is not reliant on the availability of expertly trained data scientists, thus being of particular potential benefit for low resource health-care settings. METHODS: This retrospective cohort study used retinal images from 1370 neonates admitted to a neonatal unit at Homerton University Hospital NHS Foundation Trust, London, UK, between 2008 and 2018. Images were acquired using a Retcam Version 2 device (Natus Medical, Pleasanton, CA, USA) on all babies who were either born at less than 32 weeks gestational age or had a birthweight of less than 1501 g. Each images was graded by two junior ophthalmologists with disagreements adjudicated by a senior paediatric ophthalmologist. Bespoke and code-free deep learning models (CFDL) were developed for the discrimination of healthy, pre-plus disease, and plus disease. Performance was assessed internally on 200 images with the majority vote of three senior paediatric ophthalmologists as the reference standard. External validation was on 338 retinal images from four separate datasets from the USA, Brazil, and Egypt with images derived from Retcam and the 3nethra neo device (Forus Health, Bengaluru, India). FINDINGS: Of the 7414 retinal images in the original dataset, 6141 images were used in the final development dataset. For the discrimination of healthy versus pre-plus or plus disease, the bespoke model had an area under the curve (AUC) of 0·986 (95% CI 0·973-0·996) and the CFDL model had an AUC of 0·989 (0·979-0·997) on the internal test set. Both models generalised well to external validation test sets acquired using the Retcam for discriminating healthy from pre-plus or plus disease (bespoke range was 0·975-1·000 and CFDL range was 0·969-0·995). The CFDL model was inferior to the bespoke model on discriminating pre-plus disease from healthy or plus disease in the USA dataset (CFDL 0·808 [95% CI 0·671-0·909, bespoke 0·942 [0·892-0·982]], p=0·0070). Performance also reduced when tested on the 3nethra neo imaging device (CFDL 0·865 [0·742-0·965] and bespoke 0·891 [0·783-0·977]). INTERPRETATION: Both bespoke and CFDL models conferred similar performance to senior paediatric ophthalmologists for discriminating healthy retinal images from ones with features of pre-plus or plus disease; however, CFDL models might generalise less well when considering minority classes. Care should be taken when testing on data acquired using alternative imaging devices from that used for the development dataset. Our study justifies further validation of plus disease classifiers in ROP screening and supports a potential role for code-free approaches to help prevent blindness in vulnerable neonates. FUNDING: National Institute for Health Research Biomedical Research Centre based at Moorfields Eye Hospital NHS Foundation Trust and the University College London Institute of Ophthalmology. TRANSLATIONS: For the Portuguese and Arabic translations of the abstract see Supplementary Materials section

    Population Genetic Diversity and Structure of a Naturally Isolated Plant Species, Rhodiola dumulosa (Crassulaceae)

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    Aims: Rhodiola dumulosa (Crassulaceae) is a perennial diploid species found in high-montane areas. It is distributed in fragmented populations across northern, central and northwestern China. In this study, we aimed to (i) measure the genetic diversity of this species and that of its populations; (ii) describe the genetic structure of these populations across the entire distribution range in China; and (iii) evaluate the extent of gene flow among the naturally fragmented populations. Methods: Samples from 1089 individuals within 35 populations of R. dumulosa were collected, covering as much of the entire distribution range of this species within China as possible. Population genetic diversity and structure were analyzed using AFLP molecular markers. Gene flow among populations was estimated according to the level of population differentiation. Important Findings: The total genetic diversity of R. dumulosa was high but decreased with increasing altitude. Populationstructure analysis indicated that the most closely related populations were geographically restricted and occurred in close proximity to each other. A significant isolation-by-distance pattern, caused by the naturally fragmented population distribution, was observed. At least two distinct gene pools were found in the 35 sampled populations, one composed of populations in northern China and the other composed of populations in central and northwestern China. The calculation of Nei’s gene diversity index revealed that the genetic diversity in the northern China pool (0.1972) was lower than that in th

    The permanent improvement of proteinuria and renal failure with colchicine and enalapril in a leukemic patient with renal amyloidosis secondary to ankylosing spondylitis: A review of the literature

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    Acute leukemia has been reported as secondary to radiation therapy in patients with ankylosing spondylitis (AS). AA amyloidosis secondary to AS causes progressive organ failure. Although new therapeutic choices can be used, response to therapy in secondary amyloidosis is not good enough. In AA amyloidosis, clinical symptoms partially regress with colchicine. Here, we report a patient with acute leukemia and AS. After complete remission of acute leukemia, pulmonary tuberculosis, acute renal failure and nephrotic syndrome developed. After treatment of leukemia and tuberculosis, Colchicine and enalapril therapy resulted in an improvement of clinical symptoms. He was followed up for >15 years and is doing very well and has minimal symptoms related to AS. © 2013 Lippincott Williams & Wilkins

    SIADH induced by amiodarone in a patient with heart failure

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    PubMedID: 18199281[No abstract available

    Finger-Prick Autologous Blood (FAB) Eye Drops for Dry Eye Disease: Single Masked Multi-Centre Randomised Controlled Trial

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    PURPOSE: To investigate the quantitative and qualitative efficacy of finger-prick autologous blood (FAB) eye drops versus conventional medical therapy for the treatment of severe dry eye disease (DED). METHODS: Two centre, single masked, randomised controlled trial. Sixty patients in total were recruited with thirty patients (sixty eyes) treated with FAB eye drops four times per day in addition to their conventional DED treatment, and thirty patients (fifty-eight eyes) served as control subjects on conventional treatment alone. Ocular surface disease index (OSDI), Schirmer’s test, fluorescein ocular staining grade (OCSG) Oxford schema and fluorescein tear film break-up time (TBUT), were performed at baseline, at 4 and 8 weeks. RESULTS: OSDI scores significantly decreased in the FAB arm by greater than − 17.68 (− 37.67 to − 2.96, p=0.02) compared to the control arm. There were greater improvements in OCSG and TBUT in the FAB arm but these were non-significant (p> 0.05). CONCLUSION: This feasibility study demonstrates adding FAB eye drops to conventional medical therapy for DED improves mean OSDI symptom score compared to conventional medical therapy alone. It may have particular use in settings where serum is unobtainable. An adequately powered and well-designed randomised trial is needed to further evaluate the long-term clinical benefit of FAB
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