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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.

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.

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.

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 (β = − 0.4, P = 0.04), log-albumin/creatinine ratio (β = − 0.71, P = 0.003), and with reduced estimated glomerular filtration rate (β = 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.

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

Segmentation of retinal blood vessels is a very important diagnostic procedure in ophthalmology. Segmenting blood vessels in the presence of pathological lesions is a major challenge. In this paper, an innovative approach to segment the retinal blood vessel in the presence of pathology is proposed. The method combines both supervised and unsupervised approaches in the retinal imaging context. Two innovative descriptors named local Haar pattern and modified speeded up robust features are also proposed. Experiments are conducted on three publicly available datasets named: DRIVE, STARE and CHASE DB1, and the proposed method has been compared against the state‐of‐the‐art methods. The proposed method is found about 1% more accurate than the best performing supervised method and 2% more accurate than the state‐of‐the‐art Nguyen et al.’s method.

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

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.

Diabetic retinopathy (DR), one of the major and long-term microvascular complications of diabetes, is the most common cause of vision loss and blindness in the working population of the world. Even with the management of diabetes, most patients will develop some forms of DR after approximately 20 years. However, DR is a treatable disease throughout the disease progression. To provide appropriate DR management, the USA and European countries have successfully implemented systematic early DR screening programs. At the same time, some computer-aided DR screening systems, which combine advanced DR detection algorithms and telemedicine technology, have also been developed for early-stage DR detection. Some of them have been tested in the DR screening programs. In this paper, we focus on a review of the major automatic DR screening systems which have performed large-scale evaluation rather than give an extensive review of all published DR grading algorithms. We first present the structures of the automatic systems and their supporting algorithms developed by the research groups, as well as the practices of the systems in their screening programs. We further present a more detailed review of the DR lesion detection algorithms in each system and reveal how the DR screening systems successfully practiced in clinical trials or large-scale screening programs. We also review recently new research areas as well as deep learning-based DR screening systems and compare them with the traditional lesion detection-based DR screening systems. The performances of the systems in the trials are summarized by considering the specificity and sensitivity with respect to the scale of testing datasets. At last, we will discuss future challenges.

Diabetic retinopathy (DR) is one of the leading cause of visual impairments in the working age population in the developed world. It is a complication of both types of diabetes mellitus, which affects the light perception part of the retina; and without timely treatment patients could lose their sight and eventually become blind. Automated methods for the detection and progression analysis of DR are considered as potential health-care need to stop disease propagation and to ensure improved management for DR. Aiming for the detection and progression analysis of DR, color fundus photography is considered as one of the best candidates for non-invasive imaging of the eye fundus. A list of methods has already been developed to analyse DR related changes in the retina using color fundus photographs. In this manuscript we review those automated methods. In order to accurately compare the evolution of DR over time, retinal images that are typically collected on an annual or biennial basis must be perfectly superimposed. However, in reality, for two separate photographic-eye examinations the patient is never in exactly the same position and also the camera may vary. Therefore, a registration method is applied prior to evolution computation. Knowing registration as a fundamental preprocessing step for longitudinal (over time) analysis, we also reviewed state-of-the art methods for the registration of color fundus images. The review summarizes the achievement so far and also identifies potential study areas for further improvement and future research toward more efficient and accurate DR progression analysis.

Convolutional neural network (CNN)-based methods have achieved state-of-the-art performance in glaucoma detection. Despite this, these methods are often criticized for offering no opportunity to understand how classification decisions are made. In this paper, we develop an innovative visualization strategy that allows the inherent image features contributing to glaucoma detection at different CNN layers to be understood. We also develop a set of interpretable notions to better comprehend the contributing image features involved in the disease detection process. Extensive experiments are conducted on publicly available glaucoma datasets. Results show that the optic cup is the most influential ocular component for glaucoma detection (overall Intersection over Union (IoU) score of 0.18), followed by the neuro-retinal rim (NR) with IoU score 0.17. With an overall IoU score of 0.16 vessels in the photograph also play a considerable role in the disease detection.

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.

Additional file 1: SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protocol and related documents*

Additional file 1: SPIRIT 2013 Checklist: Recommended items to address in a clinical trial protocol and related documents*

Additional file 2: Participant survey

Additional file 2: Participant survey

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.

Image registration is an important step in several retinal image analysis tasks. Robust detection, description and accurate matching of landmark points (also called keypoints) between images are crucial for successful registration of image pairs. This paper introduces a novel binary descriptor named Local Haar Patter of Bifurcation point (LHPB), so that retinal keypoints can be described more precisely and matched more accurately. LHPB uses 32 patterns that are reminiscent of Haar basis function and relies on pixel intensity test to form 256 bit binary vector. LHPB descriptors are matched using Hamming distance. Experiments are conducted on publicly available retinal image registration dataset named FIRE. The proposed descriptor has been compared with the state-of-the art Chen et al.'s method and ALOHA descriptor. Experiments show that the proposed LHPB descriptor is about 2% more accurate than ALOHA and 17% more accurate than Chen et al.'s method.

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.

Age-related macular degeneration (AMD) is one of the main reasons for visual impairment worldwide. The assessment of risk for the development of AMD requires reliable detection and quantitative mapping of retinal abnormalities that are considered as precursors of the disease. Typical signs of the latter are the so-called drusen that appear as yellowish spots in the retina. Automated detection and segmentation of drusen provide vital information about the severity of the disease. The authors propose a novel method for the detection and segmentation of drusen in colour fundus images. The method combines colour information of the object with its boundary information for the accurate detection and segmentation of drusen. To perform non-uniform illumination correction and to minimise inter-subject variability a novel colour normalisation method has been proposed. Experiments are conducted on publicly available STARE and ARIA datasets. The method achieves an overall accuracy of 96.62% which is about 4% higher than the state-of-the-art method. The sensitivity and specificity of the proposed method are 95.96 and 97.64%, respectively.

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.

Retinal images are frequently corrupted by unwanted variations in the brightness that occur due to over-all imperfections in the image acquisition process. This inhomogeneous illumination across the retina can limit the pathological information that can be gained from the image; and can lead to serious difficulties when performing image processing tasks that requires qualitative as well as quantitative analysis of feature presence on the image. On that perspective we have proposed a novel two-step approach for non-uniform and/or poor illumination correction in the context of retinal imaging. A subjective experiment was conducted to ensure that the proposed method did not create visually noticeable false color or artifacts on the images, especially on the areas that did not suffer non-uniform/poor illumination prior to correction. An objective experiment on 25,872 retinal images was performed to justify the significance of the proposed method for automated pathology detection/classification.

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.

Objective This review is designed to inform future decisions about the benefits of integrating teledentistry into routine health services, by presenting an overview of the evidence for the effectiveness and economic impact of teledentistry. Methods Two reviewers searched PubMed, EMBASE and CINAHL databases through November 2016 to identify published peer-reviewed studies in English. Teledentistry studies were included if they were; (a) controlled (randomised or non-randomised) assessment studies; and (b) compared outcomes of a teledentistry intervention in terms of clinical or economic evaluation with the outcomes of traditional clinical alternatives. The quality of the studies was evaluated using a quality appraisal tool that considered study performance and design. Results This review identified 385 publications, of which 217 full-text articles were retrieved for further inspection. Of these, only 11 articles met the inclusion criteria. Nine of the included articles showed some clinical outcomes; the other two were primarily economic analyses. The balance of these studies assesed the efficacy of teledentistry interventions rather than their effectiveness. Four studies (36%) achieved higher quality scores and have greater potential to influence health-care decision-making. To date, the most convincing published evidence regarding the efficacy of teledentistry was provided by studies on paediatric dentistry, orthodontics and oral medicine. The economic analysis referred only to cost-minimisation, suggesting that the use of teleconsultation in dentistry can be cost-saving when compared to a conventional consultation. However, high-quality economic studies on teledentistry are rare. Conclusion There is emerging evidence supporting the efficacy of teledentistry. However, there is not yet enough conclusive evidence, particularly for its effectiveness, cost-effectiveness and long-term use, to make evidence-based policy decisions on teledentistry.

Retinal vascular network pattern is unique to each individual which can be used for person identification in biometric authentication. In this study, the authors have proposed a novel biometric authentication method using retinal vascular branch, bifurcation and crossover points (i.e. feature points). The method automatically extracts the vascular network from colour retinal images and identifies these feature points. The major blood vessels characterised by width and length are identified from the segmented vascular network. For this, a novel vessel width measurement method is applied and vessels more than certain widths are selected as major vessels following an established protocol. The geometric hashing technique is developed to compute the invariant features from these feature points. They consider the feature points from major vessels which will be less susceptible to noise for modelling a basis pair and all other points together for locations in the hash table entries. The models are invariant to rotation, translation and scaling as inherited from geometric hashing. For each person, the system is trained with the models to accept or reject a claimed identity. They have tested their method on 3010 retinal images and achieved 96.64% precision and 100% recall.

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 A...

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.

Segmentation of retinal blood vessels is an important diagnostic procedure in ophthalmology. In this paper we propose an automated blood vessels segmentation method that combines both supervised and un-supervised approaches. A novel descriptor named Local Haar Pattern (LHP) is proposed to describe retinal pixel of interest. The performance of the proposed method has been evaluated on three publicly available DRIVE, STARE and CHASE_DB1 datasets. The proposed method achieves an overall segmentation accuracy of 96%, 96% and 95% respectively on DRIVE, STARE, and CHASE DB1 datasets, which are better than the state-of-the-art methods.

Bifurcation points are typically considered as landmark points for retinal image registration. Robust detection, description and accurate matching of landmark points between images are crucial for successful registration of image pairs. This paper introduces a novel descriptor named Binary Descriptor for Retinal Bifurcation Point (BDRBP), so that bifurcation point can be described and matched more accurately. BDRBP uses four patterns that are reminiscent of Haar basis function. It relies on pixel intensity difference among groups of pixels within a patch centering on the bifurcation point to form a binary string. This binary string is the descriptor. Experiments are conducted on publicly available retinal image registration dataset named FIRE. The proposed descriptor has been compared with the state-of-the art Li Chen et al.’s method for bifurcation point description. Experiments show that bifurcation points can be described and matched with an accuracy of 86–90% with BDRBP, whereas, for Li Chen et al.’s method the accuracy is 43–78%.

Registration of retinal image is a crucial and fundamental step in several medical diagnoses. In this paper we propose an innovative method for retinal image registration. The method applies log-polar transform to approximate the difference in scale and orientation among images. A novel descriptor named Combined Local Haar of Bifurcation points (CLHB) is proposed for robust description and precise matching of retinal bifurcation and cross-over points. Experiments are performed on retinal image registration datasets collected from private and public sources and consisting of a total of 484 fundus photographs (i.e. 242 pairs). The proposed method has been compared with the state-of-the-art Generalized Dual-Bootstrap Iterative Closest Point (GDP ICP), Hernandez-Matas et al., Saha et al., and Chen et al.’s methods and has been found to outperform them with a clear margin. On the publicly available FIRE dataset, our proposed method is found 2% more accurate than the best performing Saha et al.’s method. On the private dataset the method is found to be about 3% more accurate than the best performing method.

Objective This study sought to systematically review the literature for research evidence for the diagnostic accuracy of teledentistry in the detection of dental caries. Methods Two reviewers searched PubMed, EMBASE, and Scopus databases through January 2016 for comparative studies that examined the diagnostic accuracy of teledentistry for detecting caries compared with nontelemedicine alternatives. Retrieved studies were screened for inclusion criteria and were evaluated for methodological quality using the quality assessment of diagnostic accuracy studies (QUADAS-2) checklist. Results Of 287 citations identified, 10 met the preset inclusion criteria. Sensitivity and specificity were the most common measures of diagnostic accuracy used in 10 studies. Despite very limited published evidence on the diagnostic accuracy of teledentistry, the reviewed teledentistry studies showed comparable diagnostic performance compared with nontelemedicine alternatives. The average methodological quality of the selected articles is low, since none of the selected studies satisfied all 4 QUADAS-2 domains. Only 6 articles were scored as having a low risk of bias in 3 of 4 of QUADAS-2 domains. All the selected studies had low concerns regarding applicability. The main shortcoming was that in most of the selected studies, the methodology, in particular patient selection and index tests, was insufficiently described. Conclusions Teledentistry has an acceptable diagnostic performance in the detection of dental caries. However, due to the heterogeneity of the reviewed studies, the generalization of results may be difficult. Further well-designed research to investigate the effectiveness of the teledentistry approach to caries detection is needed to determine the capability of this technology in epidemiologic oral surveys.

Objectives This study aimed to determine whether intraoral photographic assessment by mid-level dental providers (MLDPs) offers a valid and reliable means of dental caries screening. Methods A mobile teledentistry model was developed to facilitate the acquisition of dental images, and transmission and reviewing of data. One hundred regularly attending patients at a dental clinic participated in the study. Following an on-site clinical examination by a senior dentist, photographs of participants' teeth were taken by a teledental assistant, using a smartphone camera. These intraoral photographs were directly uploaded from an Android App to a cloud-based server, ‘Remote-i’, using an encrypted store-and-forward telemedicine technology. The photographic assessment carried out by two independent screeners (MLDPs), was compared to the visual oral examination scores of a benchmark examiner. Results The sensitivity and specificity values for the photographic assessment method (assessed by screeners) as compared to the direct visual examination ranged from 60% to 68%, and 97% to 98%, respectively. The intra-rater reliability for the photographic assessment was almost perfect, with a kappa score of 0.89. The inter-rater reliability between the photographic and visual oral assessments ranged from moderate to substantial agreement, with kappa scores ranging from 0.57 to 0.61. Conclusion A new smartphone-based mobile teledentistry model used by mid-level dental providers shows potential for remote screening of dental caries.

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-β (Aβ) 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 Aβ 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.

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.

Exudate detection is an essential task for computer-aid diagnosis of diabetic retinopathy (DR), so as to monitor the progress of DR. In this paper, deep convolutional neural network (CNN) is adopted to achieve pixel-wise exudate identification. The CNN model is first trained with expert labeled exudates image patches and then saved as off-line classifier. In order to achieve pixel-level accuracy meanwhile reduce computational time, potential exudate candidate points are first extracted with morphological ultimate opening algorithm. Then the local region (64 × 64) surrounding the candidate points are forwarded to the trained CNN model for classification / identification. A pixel-wise accuracy of 91.92%, sensitivity of 88.85% and specificity of 96% is achieved with the proposed CNN architecture on the test database.

Objective: This study investigated the retinal arteriolar central reflex (CR, the central reflection observed in photographs of retinal vessels), which may provide information about micro-vascular health in the retina and also the brain, due to the homology between these vascular networks. The study also describes a novel computer based semi-automated technique that accurately quantifies retinal arteriolar CR and vessel width, and calculates the CR to vessel width ratio (CRR) from digital retinal photographs. Methods: Digital retinal photographs were collected from participants in the Australian Imaging, Biomarkers and Lifestyle study of ageing (AIBL), including 25 participants diagnosed with Alzheimer’s disease (AD) (age 72.4 ± 7.5 yrs, 12 male, 13 female) and 123 elderly participants without dementia (cognitively normals: CN) (age 71.6 ± 5.6 yrs, 55 male, 68 female). Using a sub-cohort of 144 (22 AD, 122 CN) with the novel CRR measures, we identified significantly higher CRR levels in AD participants (mean CRR 0.253 (SD 0.04)) as compared with CN’s (mean CRR 0.231 (SD 0.04), p = 0.025). Adjustment for APOE e4 allele status however, reduced the significance (p = 0.081). CRR was significantly higher in APOE e4 allele carriers (mean CRR 0.254 (SD 0.03) as compared with non-carriers (mean CRR 0.224 (SD 0.05), p < 0.0001). Results: These data indicate that CRR is strongly linked to APOE e4 status and exhibits a weaker, independent trend with AD diagnosis. The retina may be useful as a novel model for non-invasive monitoring of the effects of APOE e4 on the central nervous system, particularly in cerebrovascular disease.

Cortical cholinergic deficiency is prominent in Alzheimer’s disease (AD), and published findings of diminished pupil flash response in AD suggest that this deficiency may extend to the visual cortical areas and anterior eye. Pupillometry is a low-cost, noninvasive technique that may be useful for monitoring cholinergic deficits which generally lead to memory and cognitive disorders. The aim of the study was to evaluate pupillometry for early detection of AD by comparing the pupil flash response (PFR) in AD (N=14) and cognitively normal healthy control (HC,N=115) participants, with the HC group stratified according to high (N=38) and low (N=77) neocortical amyloid burden (NAB). Constriction phase PFR parameters were significantly reduced in AD compared to HC (maximum accelerationp<0.05, maximum velocityp<0.0005, average velocityp<0.005, and constriction amplitudep<0.00005). The high-NAB HC subgroup had reduced PFR response cross-sectionally, and also a greater decline longitudinally, compared to the low-NAB subgroup, suggesting changes to pupil response in preclinical AD. The results suggest that PFR changes may occur in the preclinical phase of AD. Hence, pupillometry has a potential as an adjunct for noninvasive, cost-effective screening for preclinical AD.

Current state-of-the-art diagnostic measures of Alzheimer's disease (AD) are invasive (cerebrospinal fluid analysis), expensive (neuroimaging) and time-consuming (neuropsychological assessment) and thus have limited accessibility as frontline screening and diagnostic tools for AD. Thus, there is an increasing need for additional noninvasive and/or cost-effective tools, allowing identification of subjects in the preclinical or early clinical stages of AD who could be suitable for further cognitive evaluation and dementia diagnostics. Implementation of such tests may facilitate early and potentially more effective therapeutic and preventative strategies for AD. Before applying them in clinical practice, these tools should be examined in ongoing large clinical trials. This review will summarize and highlight the most promising screening tools including neuropsychometric, clinical, blood, and neurophysiological tests.

PURPOSE: To describe the methodology and assess the reliability of novel computer-based semiautomated software that quantifies retinal arteriolar central light reflex (CR) from digital retinal photographs. METHODS: A total of 150 optic disc-centered digital color retinal photographs were selected from a population-based cross-sectional study of persons aged 40 to 80 years (the Singapore Malay Eye Study [SiMES]). Computer-assisted software was developed to quantify retinal arteriolar CR by selecting vessel edge points semiautomatically. This software then automatically computes the CR, vessel diameter, and the CR-to-vessel diameter ratio (CRR). Reliability was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman plots. Multiple linear regression analyses were performed to assess the associations between CRR and systemic and ocular factors, to further validate the novel software. RESULTS: The ICCs for the intergrader and intragrader CRR measurement were 0.76 (95% confidence interval [CI] 0.53-0.89) and 0.86 (95% CI 0.67-0.94), respectively. The ICC for intravisit repeatability was 0.87 (95% CI 0.71-0.95). In the multivariate model, a higher CRR was associated with elevated mean arterial blood pressure (per 10 mm Hg increase) (β = 0.017, P < 0.001). CONCLUSIONS: Quantitative assessment of retinal arteriolar wall opacification is a reliable method using a new computer-assisted system. This new CRR measurement system is a potentially useful tool to study retinal arteriolar abnormalities with systemic diseases.

In this editorial, four eye care professionals from diverse backgrounds and from across Australia come together to discuss if, and how, the hand down of the 2014 Australian federal government budget, announced in May of this year, has impacted on the eye care of Australians and their practice.

A population-based cross-sectional study was conducted to follow-up an earlier study which estimated the prevalence of self-reported visual disability and its impact on the quality of life (QOL) of older persons living in a rural area of Northeast Thailand based on a secondary analysis of data collected for another purpose. Self-reported difficulty with seeing was used to determine prevalence of visual disability. The WHOQOL-BREF and WHOQOL-OLD were used to assess the impact of visual disability on QOL. Fifty nine percent reported having difficulty seeing to the extent that it interfered with their daily life. Those who reported having difficulty with seeing were found to be older, disproportionately female, have lower perception of health, and to score lower on QOL than those who did not. The findings of this study differed from the earlier study. It is asserted that the findings from this latter study are likely to be more representative of the situation due to the use of a more systematic and targeted sampling procedure.

This study sought to evaluate the efficacy of a mobile teledentistry approach using a smartphone camera for remote screening of dental caries.An image acquisition Android App was created to facilitate the acquisition and transmission of dental images to a store-and-forward based telemedicine server. One hundred participants who were attending routine checkups at dental clinics were enrolled in 2014. Following a face-to-face oral screening by a screener (dentist), images of patients' teeth were obtained using a smartphone camera. These images, along with patient information, were then transmitted from the Android App to the server through the Internet for later independent assessment by two charters (off-site dentists). The assessments of these charters were then compared to the benchmark face-to-face caries assessment.Sensitivity values for the photographic method when compared to the benchmark face-to-face caries assessment were moderate, and ranged from 60% to 63%. Weighted kappa (K) as a measure of intragrader agreement for the photographic assessment was estimated as almost perfect (K = 0.84). The intergrader agreement for the photographic method compared to the face-to-face caries assessment ranged from moderate to substantial (K = 0.54-0.66).Despite some limitations, the mobile teledentistry approach has shown the potential to detect occlusal caries from photographs taken by a smartphone camera with an acceptable diagnostic performance compared to traditional face-to-face screening. This study suggests that telemedicine and cellular phone technology can be combined to create an inexpensive and reliable screening tool.

M. Estai, J. Winters, Y. Kanagasingam, J. Shiikha, H. Checker, E. Kruger and M. Tennant investigate the use of ‘mid-level dental practitioners’, such as dental therapists, to remotely screen for oral diseases using a ‘telehealth’ model.

This paper presents a novel two step approach for longitudinal (over time) registration of retinal images. Longitudinal registration is an important preliminary step to analyse longitudinal changes on the retina including disease progression. While potential overlap and minimal geometric distortion are likely in longitudinal images, identification of reliable features over time is a potential challenge for longitudinal registration. Relying on the widely accepted phenomenon that retinal vessels are more reliable over time, the proposed method aims to accurately match bifurcation and cross-over points between different timestamp images. Binary robust independent elementary features (BRIEF) are computed around bifurcation points which are then matched based on Hamming distance. Prior to computing BRIEF descriptors, a preliminary registration is performed relying on SURF key-point matching. Experiments are conducted on different image datasets containing 109 longitudinal image pairs in total. The proposed method has been found to produce accurate registration (i.e. registration with zero alignment error) for 97 % cases, which is significantly higher than the other methods in comparison. The paper also reveals the finding that both the number and distributions of accurately matching key-points pairs are important for successful registration of image pairs.

Background Improvements in acute care of stroke patients have decreased mortality, but survivors are still at increased risk of future vascular events and mitigation of this risk requires thorough assessment of the underlying factors leading to the stroke. The brain and eye share a common embryological origin and numerous similarities exist between the small vessels of the retina and brain. Recent population-based studies have demonstrated a close link between retinal vascular changes and stroke, suggesting that retinal photography could have utility in assessing underlying stroke risk factors and prognosis after stroke. Modern imaging equipment can facilitate precise measurement and monitoring of vascular features. However, use of this equipment is a challenge in the stroke ward setting as patients are frequently unable to maintain the required seated position, and pupil dilatation is often not feasible as it could potentially obscure important neurological signs of stroke progression. Materials and Methods This small study investigated the utility of a novel handheld, nonmydriatic retinal camera in the stroke ward and explored associations between retinal vascular features and stroke risk factors. This camera circumvented the practical limitations of conducting retinal photography in the stroke ward setting. Results A positive correlation was found between carotid disease and both mean width of arterioles ( r = .40, P = .00571) and venules ( r = .30, P = .0381). Conclusions The results provide further evidence that retinal vascular features are clinically informative about underlying stroke risk factors and demonstrate the utility of handheld retinal photography in the stroke ward.

Neovascularization (NV) is a definitive indicator for the onset of Proliferative Diabetic Retinopathy (PDR). The new vessels are fragile and prone to bleed, leading to high risk of sudden vision loss. Automatic detection of NV is an important task in automatic Diabetic Retinopathy (DR) screening as a consequence of the unmet requirement between the growing number of DR patients and limited number of ophthalmologists. This paper focuses on the computer aided detection of neovascularization in the optic disk region. We propose a novel image processing approach that involves vessel segmentation using multi-level Gabor filtering, feature extraction from vessel related features and texture features, and image classification based on machine learning. 21 features were extracted from each NVD image. The extracted features were trained and tested on 66 retinal images, which contains 16 NVD and 50 normal images, and achieved an sensitivity of 15/16 and specificity of 47/50.

Objective This study was conducted to evaluate the validity and reliability of intraoral photographic assessments by different members of a dental team as a means for dental screening in children.Methods The intraoral photographic records of 126 children (2 to 18 years old) were obtained from routine clinical records taken before dental treatment. Intraoral photographs were obtained using a DSLR camera and then uploaded to a cloud-based server using store-and-forward telehealth technology. Images were reviewed by an expert panel to formulate a benchmark screening baseline, to which the screeners' data were compared. The photographic assessments conducted by a mid-level dental practitioner (MLDP) and dentist, were compared to the benchmark expert panel assessment.Results The screeners' assessments by means of intraoral photography, when compared to the expert panel assessment had a sensitivity value of 82-89% and specificity value of 97%. The inter-examiner agreement between the expert panel assessment and photographic method (assessed by a dentist and MLDP), was almost perfect, with a kappa score ranging from 0.82 to 0.88. The mean DFT/dft score for the children as determined by the expert panel's review and photographic assessment ranging from 5.41 to 5.79, with mean scores between the two assessment methods not significantly different (P = 0.746).Conclusion Our results suggested that oral health professionals (other than dentists) have the potential to screen for caries from intraoral photographs with the same diagnostic accuracy and reliability as dentists. This strategy has implications for supporting the use of MLDPs such as dental therapists or hygienists to screen for oral disease using telehealth.

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 (2.7 million 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 $50 million. The fixed cost of teledentistry was $1 million and that of staff salaries (tele-assistants, charters and their supervisors, as well as information technology support was estimated to be $49 million. The estimated staff salary saved with the teledentistry model was $56 million, and the estimated travel allowance and supply expenses avoided were $16 million and $14 million respectively; an annual reduction of $85 million 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.

We describe the establishment of a new tele-eye care solution over a Broadband Satellite service, connecting metropolitan-based ophthalmologists to patients with eye conditions in rural and remote Australia. A trial of the service demonstrates the ability of the telehealth system to close the gap in access to eye care services for adult Australians living in under-served rural and remote communities, preventing needless blindness.