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1.
NPJ Digit Med ; 6(1): 19, 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36737642

RESUMO

Triage is a system used to prioritise patients as they enter the emergency department (ED) based on their need for urgent care. In recent decades, EDs have becoming increasingly overcrowded, leading to longer pre-triage waiting times for patients. E-triage interventions like kiosks have been proposed as a solution to overcrowding. We conducted a literature review into the effectiveness of kiosks in improving triage efficiency. After rigorously searching five biomedical databases and screening candidate articles in Endnote, we identified nine papers pertaining to the introduction of kiosks in emergency departments. Six articles had positive findings-with E-triage interventions improving some aspect of the triage process-such as reducing pre-triage times. Conversely, only three articles reported negative findings, such as low uptake. Consequently, EDs should consider introducing kiosks to complement the current nurse-led triage process and thereby promote better patient outcomes.

2.
Healthcare (Basel) ; 11(2)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36673646

RESUMO

Objectives: Evaluate diagnostic accuracy and feasibility of a mail-out home oximetry kit. Design: Patients were referred for both the tertiary/quaternary-centre hospital-delivered oximetry (HDO) and for the mail-out remotely-delivered oximetry (RDO). Quantitative and qualitative data were collected. The COVID-19 pandemic began during this study; therefore, necessary methodological adjustments were implemented. Setting: Patients were first evaluated in Swan Hill, Victoria. RDO kits were sent to home addresses. For the HDO, patients travelled to the Melbourne city area, received the kit, stayed overnight, and returned the kit the following morning. Participants: All consecutive paediatric patients (aged 2−18), diagnosed by a specialist in Swan Hill with obstructive sleep apnoea (OSA) on history/examination, and booked for tonsillectomy +/− adenoidectomy, were recruited. Main outcome measures: Diagnostic accuracy (i.e., comparison of RDO to HDO results) and test delivery time (i.e., days from consent signature to oximetry delivery) were recorded. Patient travel distances for HDO collection were calculated using home/delivery address postcodes and Google® Maps data. Qualitative data were collected with two digital follow-up surveys. Results: All 32 patients that had both the HDO and RDO had identical oximetry results. The HDO mean delivery time was 87.7 days, while the RDO mean delivery time was 23.6 days (p value: <0.001). Qualitatively, 3/28 preferred the HDO, while 25/28 preferred the RDO (n = 28). Conclusions: The remote option is as accurate as the hospital option, strongly preferred by patients, more rapidly completed, and also an ideal investigation delivery method during certain emergencies, such as the COVID-19 pandemic.

3.
Vision (Basel) ; 6(3)2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35893762

RESUMO

The aim of the study was to assess various retinal vessel parameters of diabetes mellitus (DM) patients and their correlations with systemic factors in type 2 DM. A retrospective exploratory study in which 21 pairs of baseline and follow-up images of patients affected by DM were randomly chosen from the Sankara Nethralaya−Diabetic Retinopathy Study (SN DREAMS) I and II datasets. Patients' fundus was photographed, and the diagnosis was made based on Klein classification. Vessel thickness parameters were generated using a web-based retinal vascular analysis platform called VASP. The thickness changes between the baseline and follow-up images were computed and normalized with the actual thicknesses of baseline images. The majority of parameters showed 10~20% changes over time. Vessel width in zone C for the second vein was significantly reduced from baseline to follow-up, which showed positive correlations with systolic blood pressure and serum high-density lipoproteins. Fractal dimension for all vessels in zones B and C and fractal dimension for vein in zones A, B and C showed a minimal increase from baseline to follow-up, which had a linear relationship with diastolic pressure, mean arterial pressure, serum triglycerides (p < 0.05). Lacunarity for all vessels and veins in zones A, B and C showed a minimal decrease from baseline to follow-up which had a negative correlation with pulse pressure and positive correlation with serum triglycerides (p < 0.05). The vessel widths for the first and second arteries significantly increased from baseline to follow-up and had an association with high-density lipoproteins, glycated haemoglobin A1C, serum low-density lipoproteins and total serum cholesterol. The central reflex intensity ratio for the second artery was significantly decreased from baseline to follow-up, and positive correlations were noted with serum triglyceride, serum low-density lipoproteins and total serum cholesterol. The coefficients for branches in zones B and C artery and the junctional exponent deviation for the artery in zone A decreased from baseline to follow-up showed positive correlations with serum triglycerides, serum low-density lipoproteins and total serum cholesterol. Identifying early microvascular changes in diabetic patients will allow for earlier intervention, improve visual outcomes and prevent vision loss.

4.
J Public Health Dent ; 82(2): 166-175, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-33495989

RESUMO

OBJECTIVES: This study was conducted to compare the use of intraoral photographs with the unaided visual dental examination as a means of dental caries detection in children. METHODS: Children aged 4- to 14-year-olds were visually examined at their schools. Following dental examinations, children had five photographs of their teeth taken using a smartphone camera. Four dental reviewers, who are different from those who visually examined the children, assessed intraoral photographs for dental caries. Sensitivity, specificity, and inter-rater reliability agreement were estimated to assess the diagnostic performance of the photographic method relative to the benchmark visual dental assessments. Caries prevalence was measured using dft/DFT (decayed and filled teeth) index. RESULTS: One hundred thirty-eight children (67 male and 71 female) were enrolled and had a mean age of 7.8 ± 2.1 years. The caries prevalence (dft/DFT > 0) using photographic dental assessments ranged from 30 percent to 39 percent but was not significantly different from the prevalence (42 percent) estimated with the visual dental examination (P ≥ 0.07). The sensitivity and specificity of the photographic method for detection of dental caries compared to visual dental assessments were 58-80 percent and 99.7-99.9 percent, respectively. The sensitivity for the photographic assessments was high in the primary dentition (63-82 percent) and children ≤7-year-olds (67-78 percent). The inter-rater reliability for the photographic assessment versus the benchmark ranged from substantial to almost perfect agreement (Kappa = 0.72-0.87). CONCLUSIONS: The photographic approach to dental screening, used within the framework of its limitations, yielded an acceptable diagnostic level of caries detection, particularly in younger children with primary dentition.


Assuntos
Cárie Dentária , Criança , Pré-Escolar , Assistência Odontológica , Cárie Dentária/diagnóstico , Cárie Dentária/epidemiologia , Feminino , Humanos , Masculino , Fotografia Dentária/métodos , Reprodutibilidade dos Testes , Smartphone
5.
BMC Fam Pract ; 22(1): 239, 2021 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-34847874

RESUMO

BACKGROUND: Despite recent incentives through Medicare (Australia's universal health insurance scheme) to increase retinal screening rates in primary care, comprehensive diabetic retinopathy (DR) screening has not been reached in Australia. The current study aimed to identify key factors affecting the delivery of diabetic retinopathy (DR) screening in Australian general practices. METHODS: A descriptive qualitative study involving in-depth interviews was carried out from November 2019 to March 2020. Using purposive snowballing sampling, 15 general practitioners (GPs) were recruited from urban and rural general practices in New South Wales and Western Australia. A semi-structured interview guide was used to collect data from participants. All interviews were conducted over the phone by one facilitator, and each interview lasted up to 45 min. The Socio-Ecological Model was used to inform the content of the interview topic guides and subsequent data analysis. Recorded data were transcribed verbatim, and thematic analysis was conducted to identify and classify recurrent themes. RESULTS: Of 15 GPs interviewed, 13 were male doctors, and the mean age was 54.7 ± 15.5 years. Seven participants were practising in urban areas, while eight were practising in regional or remote areas. All participants had access to a direct ophthalmoscope, but none owned retinal cameras. None of the participants reported performing DR screening. Only three participants were aware of the Medicare Benefits Schedule (MBS) items 12,325 and 12,326 that allow GPs to bill for retinal screening. Seven themes, a combination of facilitators and barriers, emerged from interviews with the GPs. Despite the strong belief in their role in managing chronic diseases, barriers such as costs of retinal cameras, time constraints, lack of skills to make DR diagnosis, and unawareness of Medicare incentives for non-mydriatic retinal photography made it difficult to conduct DR screening in general practice. However, several enabling strategies to deliver DR screening within primary care include increasing GPs' access to continuing professional development, subsidising the cost of retinal cameras, and the need for a champion ace to take the responsibility of retinal photography. CONCLUSION: This study identified essential areas at the system level that require addressing to promote the broader implementation of DR screening, in particular, a nationwide awareness campaign to maximise the use of MBS items, improve GPs' competency, and subsidise costs of the retinal cameras for small and rural general practices.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Adulto , Idoso , Austrália , Retinopatia Diabética/diagnóstico , Humanos , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Programas Nacionais de Saúde , Atenção Primária à Saúde
6.
Sci Rep ; 11(1): 1001, 2021 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-33441624

RESUMO

Microvascular disease and rarefaction are key pathological hallmarks of hypertension. The retina uniquely allows direct, non-invasive investigation of the microvasculature. Recently developed optical coherence tomography angiography now allows investigation of the fine retinal capillaries, which may provide a superior marker of overall vascular damage. This was a prospective cross-sectional study to collect retinal capillary density data on 300 normal eyes from 150 hypertensive adults, and to investigate possible associations with other organ damage markers. The average age of participants was 54 years and there was a greater proportion of males (85; 57%) than females. Multivariate, confounder adjusted linear regression showed that retinal capillary rarefaction in the parafovea was associated with increased pulse wave velocity (ß = - 0.4, P = 0.04), log-albumin/creatinine ratio (ß = - 0.71, P = 0.003), and with reduced estimated glomerular filtration rate (ß = 0.04, P = 0.02). Comparable significant associations were also found for whole-image vascular-density, for foveal vascular-density significant associations were found with pulse wave velocity and estimated glomerular filtration rate only. Our results indicate that retinal capillary rarefaction is associated with arterial stiffness and impaired kidney function. Retinal capillary rarefaction may represent a useful and simple test to assess the integrated burden of hypertension on the microvasculature irrespective of current blood pressure levels.


Assuntos
Artérias/patologia , Capilares/patologia , Fóvea Central/patologia , Hipertensão/patologia , Rim/patologia , Rarefação Microvascular/patologia , Vasos Retinianos/patologia , Pressão Sanguínea/fisiologia , Estudos Transversais , Feminino , Angiofluoresceinografia/métodos , Taxa de Filtração Glomerular/fisiologia , Humanos , Masculino , Microcirculação/fisiologia , Microvasos/patologia , Pessoa de Meia-Idade , Estudos Prospectivos , Análise de Onda de Pulso/métodos , Tomografia de Coerência Óptica/métodos , Rigidez Vascular/fisiologia
7.
J Clin Hypertens (Greenwich) ; 23(2): 309-316, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33340251

RESUMO

Patients with progressing chronic kidney disease (CKD) are more likely to experience cardio- and cerebrovascular events than progressing to end-stage renal disease. The authors explored whether retinal microvascular calibers differed with the degree of renal impairment and between the standard and extended optic disk and may serve as a simple additional tool for risk stratification in this highly vulnerable patient cohort. The authors analyzed central retinal arteriolar and venular equivalent calibers (CRAE, CRVE) at different retinal zones (zone B&C) using digital retinal imaging in hypertensive patients with stage 2 (n = 66) or stage 3 CKD (n = 30). Results were adjusted for age, sex, HbA1c, and 24-hour diastolic blood pressure. Mean eGFR was 77.7 ± 8.9 and 48.8 ± 7.9 ml/min/1.73 m2 for stage 2 and 3 CKD, respectively. CRAE and CRVE in zones B and C were significantly lower in patients with stage 3 CKD compared to patients with stage 2 CKD (CRAE-B:141.1 ± 21.4 vs. 130.5 ± 18.9 µm, p = .030; CRAE-C:137.4 ± 19.4 vs 129.2 ± 18.2 µm, p = .049; CRVE-B:220.8 ± 33.0 vs. 206.0 ± 28.4 µm, p = .004; and CRVE-C:215.9 ± 33.0 vs. 201.2 ± 25.1µm, p = .003). In patients with stage 2 CKD, CRAE-B was higher than CRAE-C (141.1 ± 21.4 vs. 137.4 ± 19.4µm, p < .001). In contrast, such a difference was not found in patients with stage 3 CKD. CRAE of both retinal zones correlated with eGFR for the entire cohort. In patients with stage 3 CKD, retinal narrowing is more pronounced compared to patients with stage 2 CKD. Whether the novel observation of difference in arteriolar caliber between zones B and C in stage 2 CKD could serve as an early marker of CKD progression warrants further investigation.


Assuntos
Hipertensão , Insuficiência Renal Crônica , Arteríolas , Taxa de Filtração Glomerular , Humanos , Insuficiência Renal Crônica/diagnóstico , Insuficiência Renal Crônica/epidemiologia , Vasos Retinianos/diagnóstico por imagem
8.
Front Neurosci ; 14: 556137, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33362451

RESUMO

PURPOSE: There has been increasing interest in identifying non-invasive, imaging biomarkers for neurodegenerative disorders of the central nervous system (CNS). The aim of this proof-of-concept study was to investigate whether corneal sensory nerve and dendritic cell (DC) parameters, captured using in vivo confocal microscopy (IVCM), are altered in individuals with mild cognitive impairment (MCI) and Alzheimer's disease (AD). METHODS: Fifteen participants were recruited from the Australian Imaging Biomarkers and Lifestyle (AIBL) study in Melbourne, VIC, Australia. The cohort consisted of cognitively normal (CN) individuals (n = 5), and those with MCI (n = 5) and AD (n = 5). Participants underwent a slit lamp examination of the anterior segment, followed by corneal imaging using laser-scanning in vivo confocal microscopy (IVCM) of the central and inferior whorl regions. Corneal DC density, field area, perimeter, circularity index, aspect ratio, and roundness were quantified using Image J. Quantitative data were derived for corneal nerve parameters, including nerve fiber length (CNFL), fiber density (CNFD), branch density (CNBD), and diameter. RESULTS: Corneal DC field area and perimeter were greater in individuals with MCI, relative to CN controls, in both the central and inferior whorl regions (p < 0.05 for all comparisons). In addition, corneal DCs in the whorl region of MCI eyes had lower circularity and roundness indices and a higher aspect ratio relative to CNs (p < 0.05 for all comparisons). DC density was similar across participant groups in both corneal regions. There was a trend toward lower quantitative parameters for corneal nerve architecture in the AD and MCI groups compared with CN participants, however, the inter-group differences did not reach statistical significance. Central corneal nerve diameters were similar between groups. CONCLUSION: This study is the first to report morphological differences in corneal DCs in humans with MCI. These differences were evident in both the central and mid-peripheral cornea, and in the absence of significant nerve abnormalities or a difference in DC density. These findings justify future large-scale studies to assess the utility of corneal IVCM and DC analysis for identifying early stage pathology in neurodegenerative disorders of the CNS.

9.
Int J Med Inform ; 136: 104089, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32044698

RESUMO

BACKGROUND: Ophthalmology is one of the most requested medical speciality services in the elderly population. Although numerous studies have shown the potentials of telemedicine for the provision of ophthalmology services, the extent of its usability in older adults and the aged population is not clear. The aim of this study was to investigate the characteristics and usability features of teleophthalmology for the elderly population. METHOD: We searched PubMed, Embase, Scopus and CINAHL for relevant studies since 2008. Forty-five papers met the eligibility criteria and included in this review. We used a multifaceted model to extract the data and analyze findings by cross-tabulation. RESULTS: The majority of the reviewed papers included participants of 65 years of age or older. Most of the studies were conducted in the USA (38 %). Diabetic retinopathy, glaucoma, age-related macular degeneration and cataract were the most researched eye diseases, and among the imaging technologies, retinal photography had been used the most (72 %). The studies showed teleophthalmology can improve access to specialty care, reduce the number of unnecessary visits, alleviate overloads on treatment centers, and provide more comprehensive exams. It also made services cost-saving for stakeholders and cost-effective in rural areas. However, teleophthalmology was not cost-effective for patients above 80 and low-density population areas. CONCLUSION: Evidence is lacking for the usability and effectiveness of teleophthalmology for the elderly population. The findings suggest that primary care providers in collaboration with ophthalmologists could provide more effective eye care to elderly population. Appropriate training is also necessary for primary care doctors to manage and refer older patients in a timely manner. Diagnostic value and cost-effective imaging modalities which are the core of the teleophthalmology, can be enhanced by image processing techniques and artificial intelligence.


Assuntos
Análise Custo-Benefício , Oftalmopatias/diagnóstico , Oftalmopatias/terapia , Oftalmologia/métodos , Consulta Remota/métodos , Telemedicina/organização & administração , Idoso , Gerenciamento Clínico , Oftalmopatias/economia , Humanos , Telemedicina/métodos
10.
BMC Oral Health ; 20(1): 11, 2020 01 14.
Artigo em Inglês | MEDLINE | ID: mdl-31937284

RESUMO

BACKGROUND: Despite great improvement in child oral health, some children subgroups still suffer from higher levels of dental caries. Geographic and socioeconomic barriers and the lack of access to dental care services are among common reasons for poor oral health in children. Historically in Australia, oral health therapists or dental therapists have been responsible for providing dental care for school children through the School Dental Services (SDS). The current SDS has been unable to provide sustainable dental care to all school children due to a reduction in workforce participation and limited resources. We propose a paradigm shift in the current service through the introduction of user-friendly technology to provide a foundation for sustainable dental care for school children. METHODS/DESIGN: We describe an ongoing parallel, two-armed, non-inferiority randomised controlled trial that compares routine and teledental pathway of dental care in children aged 4-15 years (n = 250). Participating schools in Western Australia will be randomly assigned to the control or teledental group, approximately three schools in each group with a maximum of 45 children in each school. All participants will first receive a standard dental examination to identify those who require urgent referrals and then their teeth will be photographed using a smartphone camera. At the baseline, children in the control group will receive screening results and advice on the pathway of dental care based on the visual dental screening while children in the teledental group will receive screening results based on the assessment of dental images. At 9 months follow-up, all participants will undergo a final visual dental screening. The primary outcomes include decay experience and proportion of children become caries active. The secondary outcomes include the diagnostic performance of photographic dental assessment and costs comparison of two pathways of dental care. DISCUSSION: The current project seeks to take advantage of mobile technology to acquire dental images from a child's mouth at school settings and forwarding images electronically to an offsite dental practitioner to assess and prepare dental recommendations remotely. Such an approach will help to prioritise high-risk children and provide them with a quick treatment pathway and avoid unnecessary referrals or travel. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry, ACTRN12619001233112. Registered 06 September 2019.


Assuntos
Assistência Odontológica/tendências , Cárie Dentária/prevenção & controle , Odontólogos/psicologia , Telemedicina , Adolescente , Austrália , Criança , Pré-Escolar , Humanos , Papel Profissional , Ensaios Clínicos Controlados Aleatórios como Assunto
11.
Appl AI Lett ; 1(1)2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36478669

RESUMO

To develop a convolutional neural network visualization strategy so that optical coherence tomography (OCT) features contributing to the evolution of age-related macular degeneration (AMD) can be better determined. We have trained a U-Net model to utilize baseline OCT to predict the progression of geographic atrophy (GA), a late stage manifestation of AMD. We have augmented the U-Net architecture by attaching deconvolutional neural networks (deconvnets). Deconvnets produce the reconstructed feature maps and provide an indication regarding the inherent baseline OCT features contributing to GA progression. Experiments were conducted on longitudinal spectral domain (SD)-OCT and fundus autofluorescence images collected from 70 eyes with GA. The intensity of Bruch's membrane-outer choroid (BMChoroid) retinal junction exhibited a relative importance of 24%, in the GA progression. The intensity of the inner retinal pigment epithelium (RPE) and BM junction (InRPEBM) showed a relative importance of 22%. BMChoroid (where the AMD feature/damage of choriocapillaris was included) followed by InRPEBM (where the AMD feature/damage of RPE was included) are the layers which appear to be most relevant in predicting the progression of AMD.

12.
Ophthalmic Epidemiol ; 26(6): 400-407, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31267797

RESUMO

Purpose: The retinal blood vessels reflect changes in the brain's micro-circulation and these changes have been shown to correlate with the incidence of diseases such as stroke, heart disease and Alzheimer's disease. Studies investigating the retinal vasculature routinely use pupil dilation with tropicamide to optimize image acquisition and quality. The aim of this study was to investigate the effects of tropicamide on retinal vascular parameters using retinal photography.Methods: The study was performed on 41 healthy young subjects of both sexes, using tropicamide to dilate only the right pupil, leaving the left as a control.Results: Pupil dilation with tropicamide resulted in reduced retinal vessel width measures based on standardized approaches, particularly reduced arteriolar caliber (p < .0005). However, closer investigation of the images revealed reduced fundus image magnification in the post-tropicamide images, based on reduced optic nerve head diameter (p < .0005) and longitudinal analysis with image registration and affine transformation (p < .0001). No change in vessel width parameters was observed after adjustment for image magnification.Conclusion: These results suggest that tropicamide does not change the width of the retinal vessels, however width parameters as measured by standard approaches may be reduced due to image magnification changes resulting from cycloplegia. In this study, improved optic nerve head segmentation for image scale conversion removed the magnification error. With this correction, the tropicamide intervention had no effect on vessel width parameters in young healthy people and could be utilized in future without affecting the results of retinal vascular analysis.


Assuntos
Midriáticos/farmacologia , Vasos Retinianos/efeitos dos fármacos , Tropicamida/farmacologia , Adulto , Feminino , Humanos , Masculino , Soluções Oftálmicas/farmacologia , Pupila/efeitos dos fármacos , Adulto Jovem
13.
Comput Med Imaging Graph ; 74: 61-71, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31022592

RESUMO

Glaucoma is rated as the leading cause of irreversible vision loss worldwide. Early detection of glaucoma is important for providing timely treatment and minimizing the vision loss. In this paper, we developed a robust segmentation method for optic disc and cup segmentation using a modified U-Net architecture, which combines the widely adopted pre-trained ResNet-34 model as encoding layers with classical U-Net decoding layers. The model was trained on the newly available RIGA dataset, and achieved an average dice value of 97.31% for disc segmentation and 87.61% for cup segmentation, comparable to that of the experts' performance for optic disc/cup segmentation and Cup-Disc-Ratio (CDR) calculation on a reserved RIGA dataset. When tested on DRISHTI-GS and RIM-ONE dataset without re-training or fine-tuning, the model achieved comparable performance to that of the state-of-the-art in literature. We have also fine-tuned the model on two databases, which achieves an average disc dice value of 97.38% and cup dice value of 88.77% for DRISHTI-GS test set, disc dice of 96.10% and cup dice of 84.45% for RIM-ONE database, which is the state-of-the-art performance on both databases in terms of cup dice and disc dice value. The advantage of the proposed method is the combination of the pre-trained ResNet and U-Net, which avoids training the network from scratch, thereby enabling fast network training with less epochs, thus further avoids over-fitting and achieves robust performance.


Assuntos
Aprendizado Profundo , Glaucoma/diagnóstico , Disco Óptico/diagnóstico por imagem , Bases de Dados Factuais , Humanos
14.
Invest Ophthalmol Vis Sci ; 59(8): 3554-3563, 2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-30025102

RESUMO

Globally, Alzheimer's disease (AD) is a growing health and economic challenge that has no effective cure. Recent clinical trials indicate that preclinical treatment may be required but a routine screening tool for AD has been elusive. Hence, a simple, yet sensitive biomarker for preclinical AD, when the disease is most likely to be amenable to treatment, is lacking. Due to several features, the eye has been explored for this purpose and, among the ocular tissues, the retina has received the most attention. Currently, major works investigating the potential AD diagnosis by detecting amyloid-ß (Aß) signatures in the retinal tissue are underway, while the anterior eye is more accessible for in vivo imaging and examination. This report provides a concise review of current literature on the anterior eye components, including the crystalline lens, cornea, and aqueous humor, in AD. We also discuss the potential for assessment of the corneal nerve structure and regeneration as well as conjunctival tissue for AD-related alterations. The crystalline lens has received considerable attention, but further research is required to confirm whether Aß accumulates in the lens and whether it mirrors brain neuropathologic changes, particularly in preclinical AD. The rich corneal neural network and conjunctival vasculature also merit exploration in future studies to shed light on their potential association with AD pathologic changes.


Assuntos
Doença de Alzheimer/diagnóstico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Segmento Anterior do Olho/metabolismo , Biomarcadores/metabolismo , Animais , Humor Aquoso/metabolismo , Córnea/metabolismo , Humanos , Cristalino/metabolismo
15.
IEEE J Biomed Health Inform ; 22(3): 886-894, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29727291

RESUMO

In this paper, the automatic detection of neovascularization in the optic disc region (NVD) for color fundus retinal image is presented. NV is the indicator for the onset of proliferative diabetic retinopathy and it is featured by the presence of new vessels in the retina. The new vessels are fragile and pose a high risk for sudden vision loss. Therefore, the importance of accurate and timely detection of NV cannot be underestimated. We propose an automatic image processing procedure for NVD detection that involves vessel segmentation using multilevel Gabor filtering, feature extraction of vessel morphological features and texture features, and image classification with support vector machine. Forty two features are extracted from each NVD image and feature selection procedure further reduce the optimal feature dimension to 18. The selected features are trained and tested on 424 retinal images, which contains 134 NVD and 290 non-NVD images. We achieved an average accuracy of 95.23%, specificity of 96.30%, sensitivity of 92.90%, and area under curve value of 98.51% on the randomly selected test set.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Aprendizado de Máquina , Disco Óptico/diagnóstico por imagem , Retinopatia Diabética/diagnóstico por imagem , Técnicas de Diagnóstico Oftalmológico , Humanos , Neovascularização Patológica/diagnóstico por imagem , Máquina de Vetores de Suporte
16.
J Digit Imaging ; 31(6): 869-878, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29704086

RESUMO

Fundus images obtained in a telemedicine program are acquired at different sites that are captured by people who have varying levels of experience. These result in a relatively high percentage of images which are later marked as unreadable by graders. Unreadable images require a recapture which is time and cost intensive. An automated method that determines the image quality during acquisition is an effective alternative. To determine the image quality during acquisition, we describe here an automated method for the assessment of image quality in the context of diabetic retinopathy. The method explicitly applies machine learning techniques to access the image and to determine 'accept' and 'reject' categories. 'Reject' category image requires a recapture. A deep convolution neural network is trained to grade the images automatically. A large representative set of 7000 colour fundus images was used for the experiment which was obtained from the EyePACS that were made available by the California Healthcare Foundation. Three retinal image analysis experts were employed to categorise these images into 'accept' and 'reject' classes based on the precise definition of image quality in the context of DR. The network was trained using 3428 images. The method shows an accuracy of 100% to successfully categorise 'accept' and 'reject' images, which is about 2% higher than the traditional machine learning method. On a clinical trial, the proposed method shows 97% agreement with human grader. The method can be easily incorporated with the fundus image capturing system in the acquisition centre and can guide the photographer whether a recapture is necessary or not.


Assuntos
Retinopatia Diabética/diagnóstico por imagem , Fundo de Olho , Processamento de Imagem Assistida por Computador/métodos , Retina/diagnóstico por imagem , Telemedicina/métodos , Algoritmos , Humanos , Aprendizado de Máquina , Redes Neurais de Computação
17.
J Med Syst ; 42(4): 57, 2018 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-29455260

RESUMO

In this paper we systematically evaluate the performance of several state-of-the-art local feature detectors and descriptors in the context of longitudinal registration of retinal images. Longitudinal (temporal) registration facilitates to track the changes in the retina that has happened over time. A wide number of local feature detectors and descriptors exist and many of them have already applied for retinal image registration, however, no comparative evaluation has been made so far to analyse their respective performance. In this manuscript we evaluate the performance of the widely known and commonly used detectors such as Harris, SIFT, SURF, BRISK, and bifurcation and cross-over points. As of descriptors SIFT, SURF, ALOHA, BRIEF, BRISK and PIIFD are used. Longitudinal retinal image datasets containing a total of 244 images are used for the experiment. The evaluation reveals some potential findings including more robustness of SURF and SIFT keypoints than the commonly used bifurcation and cross-over points, when detected on the vessels. SIFT keypoints can be detected with a reliability of 59% for without pathology images and 45% for with pathology images. For SURF keypoints these values are respectively 58% and 47%. ALOHA descriptor is best suited to describe SURF keypoints, which ensures an overall matching accuracy, distinguishability of 83%, 93% and 78%, 83% for without pathology and with pathology images respectively.


Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Retina/fisiopatologia , Retinoscopia/métodos , Algoritmos , Humanos , Reprodutibilidade dos Testes , Fatores de Tempo
18.
Int Dent J ; 68(4): 262-268, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29383697

RESUMO

OBJECTIVE: To estimate the scale of resource transfer that could be achieved by screening low-risk schoolchildren using teledentistry rather than using traditional visual dental examination. METHODS: This study was based on a previous cost-minimisation study that compared the costs of two dental-screening approaches (visual and teledentistry). The data for the population of children 5-14 years of age was obtained from the Australian Bureau of Statistics and was divided across Australia according to statistical local area (SA2). The cost models (for teledentistry and visual screening) for each SA2 relative to the state, Remoteness Area (RA) and Socio-Economic Index for Area (SEIFA) indexes were estimated. The geographical information system was used to superimpose modelled cost data on the geographical map to provide a visual presentation of the data. Resource transfer scenarios, based on risk minimisation, were then developed and analysed. RESULTS: This study demonstrated a suboptimal allocation of dental-care resources, such that children living in high socio-economic areas (major cities) with low disease burdens consuming half of the estimated resources of a universal visual dental screening system. The findings suggest that utilising teledentistry screening for low-risk children has the potential to free up $40 million per annum. Such resources can be reallocated to increase care access and improve the quality of dental services for vulnerable children. CONCLUSION: To reduce inequalities in dental health within a community, scarce health-care resources should be targeted at the population at most risk. These findings can be used to inform policymakers, guide the appropriate distribution of scarce resources and target dental services to benefit high-need children.


Assuntos
Assistência Odontológica para Crianças/economia , Custos de Cuidados de Saúde , Programas de Rastreamento/economia , Alocação de Recursos/economia , Serviços de Saúde Escolar/economia , Telemedicina/economia , Adolescente , Austrália , Criança , Pré-Escolar , Redução de Custos , Assistência Odontológica para Crianças/organização & administração , Humanos , Modelos Econômicos , Serviços de Saúde Escolar/organização & administração
19.
J Digit Imaging ; 31(4): 553-561, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29209841

RESUMO

Retinal fundus images are often corrupted by non-uniform and/or poor illumination that occur due to overall imperfections in the image acquisition process. This unwanted variation in brightness limits the pathological information that can be gained from the image. Studies have shown that poor illumination can impede human grading in about 10~15% of retinal images. For automated grading, the effect can be even higher. In this perspective, we propose a novel method for illumination correction in the context of retinal imaging. The method splits the color image into luminosity and chroma (i.e., color) components and performs illumination correction in the luminosity channel based on a novel background estimation technique. Extensive subjective and objective experiments were conducted on publicly available DIARETDB1 and EyePACS images to justify the performance of the proposed method. The subjective experiment has confirmed that the proposed method does not create false color/artifacts and at the same time performs better than the traditional method in 84 out of 89 cases. The objective experiment shows an accuracy improvement of 4% in automated disease grading when illumination correction is performed by the proposed method than the traditional method.


Assuntos
Fundo de Olho , Aumento da Imagem/métodos , Processamento de Imagem Assistida por Computador/métodos , Fotografação/métodos , Doenças Retinianas/diagnóstico por imagem , Artefatos , Diagnóstico por Imagem/métodos , Feminino , Humanos , Masculino , Imagem Óptica/métodos , Doenças Retinianas/patologia , Medição de Risco , Sensibilidade e Especificidade
20.
Aust Health Rev ; 42(5): 482-490, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28578759

RESUMO

Objective The aim of the present study was to compare the costs of teledentistry and traditional dental screening approaches in Australian school children. Methods A cost-minimisation analysis was performed from the perspective of the oral health system, comparing the cost of dental screening in school children using a traditional visual examination approach with the cost of mid-level dental practitioners (MLDPs), such as dental therapists, screening the same cohort of children remotely using teledentistry. A model was developed to simulate the costs (over a 12-month period) of the two models of dental screening for all school children (2.7million children) aged 5-14 years across all Australian states and territories. The fixed costs and the variable costs, including staff salary, travel and accommodation costs, and cost of supply were calculated. All costs are given in Australian dollars. Results The total estimated cost of the teledentistry model was $50million. The fixed cost of teledentistry was $1million and that of staff salaries (tele-assistants, charters and their supervisors, as well as information technology support was estimated to be $49million. The estimated staff salary saved with the teledentistry model was $56million, and the estimated travel allowance and supply expenses avoided were $16million and $14million respectively; an annual reduction of $85million in total. Conclusions The present study shows that the teledentistry model of dental screening can minimise costs. The estimated savings were due primarily to the low salaries of dental therapists and the avoidance of travel and accommodation costs. Such savings could be redistributed to improve infrastructure and oral health services in rural or other underserved areas. What is known about the topic? Caries is a preventable disease, which, if it remains untreated, can cause significant morbidity requiring costly treatment. Regular dental screening and oral health education have the great potential to improve oral health and save significant resources. The use of role substitution, such as using MLDPs to provide oral care has been well acknowledged worldwide because of their ability to provide safe and effective care. The teledentistry approach for dental screening offers a comparable diagnostic performance to the traditional visual approach. What does this paper add? The results of the present study suggest that teledentistry is a practical and economically viable approach for mass dental screening not only for isolated communities, but also for underserved urban communities. The costs of the teledentistry model were substantially lower than the costs associated with a conventional, face-to-face approach to dental screening in both remote and urban areas. The primary driver of net savings is the low salary of MLDPs and avoidance of travel and overnight accommodation by MLDPs. What are the implications for practitioners? The use of lower-cost MLDPs and a teledentistry model for dental screening has the potential to save significant economic and human resources that can be redirected to improve infrastructure and oral care services in underserved regions. In the absence of evidence of the economic usefulness of teledentistry, studies such as the present one can increase the acceptance of this technology among dental care providers and guide future decisions on whether or not to implement teledentistry services.


Assuntos
Redução de Custos , Assistência Odontológica para Crianças/economia , Telemedicina/economia , Adolescente , Austrália , Criança , Pré-Escolar , Redução de Custos/métodos , Assistência Odontológica para Crianças/métodos , Custos de Cuidados de Saúde/estatística & dados numéricos , Humanos , Modelos Organizacionais , Telemedicina/métodos
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