An image-based eyelid lesion management service-evaluation of a pilot.

BACKGROUND/AIMS: Oculoplastics is a predominantly visual specialty and many of the pathologies can be diagnosed based on external appearance. An image-based eyelid lesion management service was piloted to reduce the number of patients who would require outpatient clinic review. The aim of this study was to determine its accuracy and feasibility, both as a hospital-based and community optometrist-based service. If successful, the service was envisaged to significantly reduce the number of patients that require face-to-face (F2F) review, in accordance with current post-COVID-19 principles of social distancing. METHODS: Patients with lid lesions attending an oculoplastics clinic were assessed by consultant oculoplastic surgeons in an F2F consultation (Arm A). The lesions were photographed by a professional clinical photographer (Arm B) and by an optometrist with a handheld digital camera (Arm C). These images were reviewed by independent consultants masked to the outcome of the F2F clinical encounter. Data were collected prospectively including patient demographics, diagnosis, suspicion of malignancy and management. The image-based clinic results were compared to the F2F clinic results. RESULTS: Ninety-five patients were included. Clinical diagnoses were compared for intra-observer variability and substantial agreement was demonstrated between gold-standard F2F clinic visit (Arm A) and Arm B (Ƙ = 0.708) and C (Ƙ = 0.776). There was no statistically significant difference in the rate of discharge and all cases of malignancy were either identified or flagged for F2F review in the image-based arms. CONCLUSION: This pilot demonstrated substantial diagnostic agreement of image-based diagnoses with F2F consultation and image review alone did not miss any cases of malignancy.

Sensitivity analysis of an urban stormwater microorganism model.

This paper presents the sensitivity analysis of a newly developed model which predicts microorganism concentrations in urban stormwater (MOPUS--MicroOrganism Prediction in Urban Stormwater). The analysis used Escherichia coli data collected from four urban catchments in Melbourne, Australia. The MICA program (Model Independent Markov Chain Monte Carlo Analysis), used to conduct this analysis, applies a carefully constructed Markov Chain Monte Carlo procedure, based on the Metropolis-Hastings algorithm, to explore the model's posterior parameter distribution. It was determined that the majority of parameters in the MOPUS model were well defined, with the data from the MCMC procedure indicating that the parameters were largely independent. However, a sporadic correlation found between two parameters indicates that some improvements may be possible in the MOPUS model. This paper identifies the parameters which are the most important during model calibration; it was shown, for example, that parameters associated with the deposition of microorganisms in the catchment were more influential than those related to microorganism survival processes. These findings will help users calibrate the MOPUS model, and will help the model developer to improve the model, with efforts currently being made to reduce the number of model parameters, whilst also reducing the slight interaction identified.

Comparative survival of enteric indicators, E. coli and somatic and F-RNA bacteriophages on turf-grass irrigated with recycled water.

The aim of this study was to elucidate whether the current withholding period of 4 hours following irrigation of public recreational areas with some classes of recycled water, as prescribed in some Australian state regulations, is valid or whether the holding time can be reduced under specified ambient conditions. A secondary objective was to evaluate laboratory simulations of ambient field conditions for microbial survival experiments. Results suggest that the currently prescribed 4 hour withholding period achieves a reduction of health risk associated with bacterial enteric pathogens that would not otherwise occur if the withholding period was reduced. However, this may not be the case for viral enteric pathogens as the survival of bacteriophages, PRD-1 and MS-2 on turf-grass did not significantly change even after 6 hours, except PRD-1 under high solar conditions. These results suggest that bacteriophages, PRD-1 and MS-2 are more conservative indicators of enteric pathogen survival on UV exposed turf-grass compared with E. coli. The simulations of field conditions in the laboratory were somewhat problematic, with the variations in natural conditions that occur temporally, sometimes for short periods, difficult to reproduce.

Uncertainties in stormwater E. coli levels.

Although water-quality monitoring programs have been widely used to identify and understand the level of pollution in urban stormwater systems, these data are often used without due consideration of the inherent uncertainties contained within these measurements. This study focuses on the uncertainties associated with the monitored levels of Escherichia coli, a common microbial indicator, in urban stormwater. Four sites located in Melbourne, Australia, were used to assess the uncertainty of six stormwater flow and E. coli variables: (1) discrete E. coli concentration, (2) stormwater flow rate, (3) stormwater event volume, (4) event mean concentration (EMC) of E. coli (i.e. a flow-weighted average of an event's E. coli concentrations), (5) E. coli load for each measured event, and (6) site mean E. coli concentration (SMC) (i.e. a volume-weighted average of the E. coli EMCs). Uncertainties of discrete E. coli samples were greater than 30%, while the uncertainty in stormwater flow measurements averaged greater than 97%, mainly due to the high uncertainties in measurements of very low flows. Propagation of these uncertainties, through their respective formulas, found that E. coli EMC uncertainties varied between 10% and 52% and that uncertainties relating to SMC estimates ranged from 35% to 55%. These results show the importance of considering uncertainty when using monitored data sets for any application, including those relating to stormwater management decisions. Suggestions are made about how to increase the accuracies of E. coli monitoring in urban stormwater and how to balance the different sources of uncertainties so that the overall combined uncertainties are minimised while keeping costs at a minimum.

Escherichia coli in urban stormwater: explaining their variability.

The development of a model that predicts the levels of microorganisms in urban stormwater will aid in the assessment of health risks when using stormwater for both recreational uses and as an alternate water resource. However, the development of such a model requires an understanding of the dominant processes that influence the behaviour of microorganisms in urban systems. Using simple and multiple regression analyses this paper determines the dominant processes which affect the inter-event variability of the microbial indicator Escherichia coli (E. coli ) in four urbanised catchments. The results reveal that a number of antecedent climatic conditions, together with rainfall intensity, can significantly explain the inter-event variation in wet weather E. coli levels.

An investigation of rainwater tanks quality and sediment dynamics.

Rainwater tanks are being introduced into urban areas in Australia to supplement centralised potable supply systems. A pilot scale tank study and a full-scale field tank study found that heavy metal concentrations in water samples taken from the tank's supply point can, in some cases, exceed levels recommended by guidelines. Both studies also found very high concentrations of heavy metals in the sediments accumulated at the base of rainwater tanks. Laboratory experiments are underway to investigate sediment transport processes within a full-scale tank. Preliminary results demonstrate the effect of sediment resuspension on the quality of water released from the tank outlet. Improved tank designs that reduce sediment resuspension and mitigate impacts on water quality are the focus of future work.

Innovative sewerage solutions for small rural towns.

The development and implementation of alternative wastewater servicing approaches in rural communities in Australia appears more feasible than in larger urban developments as many rural centres rely on septic tanks and surface discharge of greywater. This method of disposal creates many environmental, social and economic issues and is seen to limit potential for growth in many towns. This paper describes a generic methodology for the selection of innovative sewerage options for six regional towns in Victoria, Australia. The method includes consultation with stakeholders, multi-criteria assessment and concept design of the most favourable option. Despite the broad range of initial wastewater servicing options presented which included cluster-scale systems, upgrade of existing systems, greywater reuse and alternative collection, the outcome for five of the six towns was a modified centralised collection system as the preferred option. Lack of robust and reliable data on the human health risks and environmental impacts of alternative systems were identified as the primary data gaps in the sustainability assessment. In addition, biases in the assessment method due to stakeholder perceptions were found to be an additional issue.

Clinical and immunopathological corneal phenotype in homozygotes for the BIGH3 R124H mutation.

A family was previously reported as suffering from severe granular dystrophy. The phenotypic picture suggested a mix of homozygous and heterozygous family members. Genetic analysis confirms the homozygousity in the patients most severely affected, but shows the disease state to be one of Avellino corneal dystrophy. The previous case reports are extended immunohistological staining using polyclonal antibodies raised against keratofepithelin. This genotype/phenotype correlation study is consistent with incomplete dominance.

UVQ: a tool for assessing the water and contaminant balance impacts of urban development scenarios.

This paper presents the water and contaminant daily simulation model of the total water cycle, called UVQ. The model has been developed to provide a means for rapidly assessing conventional and nonconventional approaches to providing water supply, stormwater and wastewater services to urban allotments, neighbourhoods and study areas. The model is placed the context of other such models developed internationally through a brief literature review. This is followed by a description of the model and output examples, which is used to illustrate the utility of the model. UVQ is an effective preliminary assessment tool for determining the impacts of urban development options on the total water cycle, as well as the performance of a wide range of non-conventional demand and supply side management techniques. It compliments other aspects of an environmental assessment of options, along with more traditional aspects such as infrastructure costing.

Small scale water recycling systems--risk assessment and modelling.

This paper aims to use quantitative risk analysis, risk modelling and simulation modelling tools to assess the performance of a proprietary single house grey water recycling system. A preliminary Hazard and Operability study (HAZOP) identified the main hazards, both health related and economic, associated with installing the recycling system in a domestic environment. The health related consequences of system failure were associated with the presence of increased concentrations of micro-organisms at the point of use, due to failure of the disinfection system and/or the pump. The risk model was used to assess the increase in the probability of infection for a particular genus of micro-organism, Salmonella spp, during disinfection failure. The increase in the number of cases of infection above a base rate rose from 0.001% during normal operation, to 4% for a recycling system with no disinfection. The simulation model was used to examine the possible effects of pump failure. The model indicated that the anaerobic COD release rate in the system storage tank increases over time and dissolved oxygen decreases during this failure mode. These conditions are likely to result in odour problems.

Partial oxidation by ozone to remove recalcitrance from wastewaters--a review.

Xenobiotic organics produced by modern industrial processes resist conventional biological wastewater treatment. Ozone pretreatment to improve biodegradation via partial oxidation is a potential solution for this recalcitrance. Ozone forms no additional sludge, removes colour and has two modes of action that can be utilised according to the wastewater constituents. The preozonation of a variety of wastewaters and model compounds is reviewed here. Of the industrial processes examined, the associated recalcitrant organic compounds were generally halogenated heterocyclic or nitrogenous aromatics, aliphatic polymers or polyaromatics. Initial optimisation of ozone dose ensured the occurrence of partial oxidation, where over 90% parent compound transformation was required to give best results in the subsequent biological process. Ozonation intermediate and end-products included ketones, aldehydes and organic acids that were more biodegradable than the parent compounds. Biodegradability improvement was assessed using TOC, COD, BOD, BOD/COD ratio and OUR. Actual process feasibility and performance was evaluated using various combined ozonation-biodegradation trials; textile dying and finishing effluent being one area of application. Kinetic studies of chemical and biological stages facilitated process optimisation and can assist scale-up. The main factors affecting ozonation performance were pH, the nature and concentration of oxidisable organics, ozone dose, competition between the target compound and biodegradable by-products, the presence of oxidant scavengers, and the efficiency of ozone mass transfer. The formation of toxic or recalcitrant by-products has been found to occur in some cases, necessitating knowledge of wastewater constituents and trials on a site-by-site basis.

Simultaneous bilateral cataract extraction.

PURPOSE: To evaluate the visual outcome and safety of simultaneous bilateral cataract extraction. SETTING: Stobhill Hospital NHS Trust, Glasgow, United Kingdom. METHODS: This retrospective case review comprised 259 consecutive patients (518 eyes) who had simultaneous bilateral cataract surgery. Surgeries included bilateral extracapsular procedures, uniocular extracapsular procedures performed simultaneously with a different type of intraocular lens surgery in the other eye, and 1 bilateral intracapsular procedure. Outcome measures were postoperative best spectacle-corrected visual acuity (BSCVA), intraoperative and postoperative complication rates, and conjunctival swab culture results. RESULTS: Eighty-three percent of patients (75% of eyes) with measured preoperative and postoperative BSCVA achieved an acuity of 6/12 or better. Intraoperative and postoperative complication rates were similar to those in previous reports of unilateral extracapsular surgery and simultaneous bilateral cataract surgery. Endophthalmitis occurred in 1 eye (0.19%). There were no bilateral complications that resulted in visual loss. Cultures were positive from 42% of conjunctival swabs; 81% of positive cultures were coagulase-negative Staphylococcus and 10% were Staphylococcus aureus. CONCLUSIONS: Simultaneous bilateral cataract surgery did not lead to an increased incidence of serious intraoperative or postoperative complications, and visual acuity results were good.

Lack of evidence for systemic toxicity following topical chloramphenicol use.

There has been considerable controversy regarding the safety of topical chloramphenicol in ophthalmic practice. The evidence for associated haematopoietic toxicity in idiosyncratic and dose-dependent forms was reviewed. The 7 cases of idiosyncratic haematopoietic reactions associated with topical chloramphenicol reported in the literature are refutable evidence for the existence of such a response. In Scotland, despite extensive prescription of topical chloramphenicol, the incidence of acquired aplastic anaemia was found to be low, as were associated reports of blood dyscrasias throughout the UK. The epidemiology of acquired aplastic anaemia failed to make an association with topical chloramphenicol use. High-performance liquid chromatography (minimum detection limit 1 mg/l) was used to investigate whether serum accumulation of chloramphenicol occurred after topical therapy in 40 patients. The mean dose of chloramphenicol eye drops used after 1 week of treatment was 8.0 mg, and after 2 weeks, 15.3 mg. As expected, chloramphenicol failed to accumulate to detectable levels. This supported the view that topical chloramphenicol was not a risk factor for inducing dose-related bone marrow toxicity. Calls for the abolition of treatment with topical chloramphenicol based on current data are not supported.

Pulfrich revisited.

The Pulfrich phenomenon is a stereo-illusion resulting from latency disparities in the visual pathways. It is common after optic neuritis, but is also to be found with other conditions. The symptoms are often difficult for the patient to explain and for the physician to understand. Symptoms may be sufficiently disturbing to significantly interfere with a patient's life (e.g., prevention of driving). Treatment with the use of monocular tints is simple and effective.