The Royal College of Ophthalmologists' National Ophthalmology Database Study of Cataract Surgery: Report 13, monitoring post-cataract surgery endophthalmitis rates-the rule of X.

BACKGROUND: Cataract surgical safety has improved over recent decades, with endophthalmitis rates before 2006 typically 0.13-0.15% compared with the most recent UK national estimate of 0.02%. There remains, however, substantial variation in reported rates from different centres. Due to the low event rate, this disparity may not be noticed and opportunities to improve therefore be missed. We propose a method of monitoring post-cataract endophthalmitis rates that would help centres with higher rates identify this. METHODS: A statistical tool, available to download or use online, permits comparison of local endophthalmitis rate with the estimated UK rate of 0.02%. Centres are encouraged to maintain a register of endophthalmitis cases, and when the number reaches a threshold (X cases), either in a certain time period or in a fixed number of procedures, then the centre can consider itself as an outlier and trigger local investigations to improve infection control. RESULTS: Example outputs are offered, such as for a unit doing 5000 cataracts annually, a value of X is suggested such that the third case of endophthalmitis (X = 3) in a 12-month period would give 85% confidence, the fourth case 90% confidence and the fifth case 95% confidence that the true endophthalmitis rate for that unit was higher than the national average. CONCLUSIONS: This statistical tool provides a basis for units to set a threshold number of cases of endophthalmitis within a given period that would trigger local processes, thus helping inform local monitoring processes for this rare but potentially catastrophic complication of cataract surgery.

Microbiome in Behcet's syndrome.

This review will discuss the current understanding of the role of microbiomes in Behcet's Syndrome, their influence on immune response and disease and potential future studies.

Deep Metagenomic Sequencing for Endophthalmitis Pathogen Detection Using a Nanopore Platform.

PURPOSE: To evaluate the utility of nanopore sequencing for identifying potential causative pathogens in endophthalmitis, comparing culture results against full-length 16S rRNA nanopore sequencing (16S Nanopore), whole genome nanopore sequencing (Nanopore WGS), and Illumina (Illumina WGS). DESIGN: Cross-sectional diagnostic comparison. METHODS: Patients with clinically suspected endophthalmitis underwent intraocular vitreous biopsy as per standard care. Clinical samples were cultured by conventional methods, together with full-length 16S rRNA and WGS using nanopore and Illumina sequencing platforms. RESULTS: Of 23 patients (median age 68.5 years [range 47-88]; 14 males [61%]), 18 cases were culture-positive. Nanopore sequencing identified the same cultured organism in all of the culture-positive cases and identified potential pathogens in two culture-negative cases (40%). Nanopore WGS was able to additionally detect the presence of bacteriophages in three samples. The agreements at genus level between culture and 16S Nanopore, Nanopore WGS, and Illumina WGS were 75%, 100%, and 78%, respectively. CONCLUSIONS: Whole genome sequencing has higher sensitivity and provides a viable alternative to culture and 16S sequencing for detecting potential pathogens in endophthalmitis. Moreover, WGS has the ability to detect other potential pathogens in culture-negative cases. Whilst Nanopore and Illumina WGS provide comparable data, nanopore sequencing provides potential for cost-effective point-of-care diagnostics.

Gut Dysbiosis in Ocular Mucous Membrane Pemphigoid.

Mucous Membrane Pemphigoid is an orphan multi-system autoimmune scarring disease involving mucosal sites, including the ocular surface (OcMMP) and gut. Loss of tolerance to epithelial basement membrane proteins and generation of autoreactive T cell and/or autoantibodies are central to the disease process. The gut microbiome plays a critical role in the development of the immune system. Alteration in the gut microbiome (gut dysbiosis) affects the generation of autoreactive T cells and B cell autoantibody repertoire in several autoimmune conditions. This study examines the relationship between gut microbiome diversity and ocular inflammation in patients with OcMMP by comparing OcMMP gut microbiome profiles with healthy controls. DNA was extracted from faecal samples (49 OcMMP patients, 40 healthy controls), amplified for the V4 region of the 16S rRNA gene and sequenced using Illumina Miseq platform. Sequencing reads were processed using the bioinformatics pipeline available in the mothur v.1.44.1 software. After adjusting for participant factors in the multivariable model (age, gender, BMI, diet, proton pump inhibitor use), OcMMP cohort was found to be associated with lower number of operational taxonomic units (OTUs) and Shannon Diversity Index when compared to healthy controls. Within the OcMMP cohort, the number of OTUs were found to be significantly correlated with both the bulbar conjunctival inflammation score (p=0.03) and the current use of systemic immunotherapy (p=0.02). The linear discriminant analysis effect size scores indicated that Streptococcus and Lachnoclostridium were enriched in OcMMP patients whilst Oxalobacter, Clostridia uncultured genus-level group (UCG) 014, Christensenellaceae R-7 group and butyrate-producing bacteria such as Ruminococcus, Lachnospiraceae, Coprococcus, Roseburia, Oscillospiraceae UCG 003, 005, NK4A214 group were enriched in healthy controls (Log10 LDA score < 2, FDR-adjusted p <0.05). In conclusion, OcMMP patients have gut dysbiosis correlating with bulbar conjunctival inflammation and the use of systemic immunotherapies. This provides a framework for future longitudinal deep phenotyping studies on the role of the gut microbiome in the pathogenesis of OcMMP.

Low density neutrophils are increased in patients with Behçet's disease but do not explain differences in neutrophil function.

BACKGROUND: Behçet's disease (BD) is a multisystem autoinflammatory disease characterised by mucosal ulceration, ocular, neural, joint and skin inflammation. The cause of BD is not known but there is a strong genetic association with HLA-B*51, IL10 and IL23R. Neutrophils are a first line of defence against invading pathogens and have been described as activated in patients with BD. Neutrophils can now be separated into different subsets, such as low density (LDN) and normal density (NDN) that have diverse functional roles. We wished to address neutrophil heterogeneity in patients with BD. METHODS: Peripheral blood neutrophils were obtained from 32 BD patients and 37 healthy aged-matched controls. Percoll isolation was used to isolate all neutrophils, while Ficol-Hypaque was used to obtain LDN and NDN. Phagocytic capacity and production of reactive oxygen species (ROS), and neutrophil extracellular traps (NET) stimulated with phorbol 12-myristate 13-acetate (PMA) and Escherichia coli (E.coli) were assessed in both groups. RESULTS: We have demonstrated reduced phagocytic capacity and ROS production but greater NET production by total neutrophils stimulated with PMA or E.coli from BD patients in comparison with healthy controls. Patients with BD had elevated numbers of LDN and lower number of NDN compared with healthy controls. However, both neutrophil subsets showed the same reduced ROS production and phagocytic function as total neutrophils in both groups. CONCLUSION: Our novel findings indicate that the neutrophil population in BD is heterogeneous and the increased number of LDN in combination with greater NET production may contribute to the inflammatory response and pathogenesis.

Behçet's Disease-Do Microbiomes and Genetics Collaborate in Pathogenesis?

Behçet's disease (BD) is a multisystem autoinflammatory condition characterized by mucosal ulceration, breakdown of immune privilege sites and vasculitis. A genetic basis for BD has been described in genome-wide and validation studies. Similarly, dysbiosis of oral and gut microbiomes have been associated with BD. This review will describe links between genetic polymorphisms in genes encoding molecules involved in gut biology and changes seen in microbiome studies. A potential decrease in bacterial species producing short chain fatty acids linked to mutations in genes involved in their production suggests a potential therapy for BD.

Evaluation of full-length nanopore 16S sequencing for detection of pathogens in microbial keratitis.

BACKGROUND: Microbial keratitis is a leading cause of preventable blindness worldwide. Conventional sampling and culture techniques are time-consuming, with over 40% of cases being culture-negative. Nanopore sequencing technology is portable and capable of generating long sequencing reads in real-time. The aim of this study is to evaluate the potential of nanopore sequencing directly from clinical samples for the diagnosis of bacterial microbial keratitis. METHODS: Using full-length 16S rRNA amplicon sequences from a defined mock microbial community, we evaluated and benchmarked our bioinformatics analysis pipeline for taxonomic assignment on three different 16S rRNA databases (NCBI 16S RefSeq, RDP and SILVA) with clustering at 97%, 99% and 100% similarities. Next, we optimised the sample collection using an ex vivo porcine model of microbial keratitis to compare DNA recovery rates of 12 different collection methods: 21-gauge needle, PTFE membrane (4 mm and 6 mm), Isohelix™ SK-2S, Sugi® Eyespear, Cotton, Rayon, Dryswab™, Hydraflock®, Albumin-coated, Purflock®, Purfoam and Polyester swabs. As a proof-of-concept study, we then used the sampling technique that provided the highest DNA recovery, along with the optimised bioinformatics pipeline, to prospectively collected samples from patients with suspected microbial keratitis. The resulting nanopore sequencing results were then compared to standard microbiology culture methods. RESULTS: We found that applying alignment filtering to nanopore sequencing reads and aligning to the NCBI 16S RefSeq database at 100% similarity provided the most accurate bacterial taxa assignment. DNA concentration recovery rates differed significantly between the collection methods (p < 0.001), with the Sugi® Eyespear swab providing the highest mean rank of DNA concentration. Then, applying the optimised collection method and bioinformatics pipeline directly to samples from two patients with suspected microbial keratitis, sequencing results from Patient A were in agreement with culture results, whilst Patient B, with negative culture results and previous antibiotic use, showed agreement between nanopore and Illumina Miseq sequencing results. CONCLUSION: We have optimised collection methods and demonstrated a novel workflow for identification of bacterial microbial keratitis using full-length 16S nanopore sequencing.

Socioeconomic deprivation and serious ocular trauma in Scotland: a national prospective study.

OBJECTIVE: To identify the population at risk of serious ocular trauma by exploring relationships with socioeconomic factors. DESIGN: National, prospective, population-based, cross-sectional and follow-up study. PARTICIPANTS: Patients with serious ocular trauma requiring hospital admission in Scotland. METHODS: Case definition and ascertainment-cases of serious ocular trauma necessitating admission to hospital under the care of a consultant ophthalmologist were identified using the British Ophthalmological Surveillance Unit reporting scheme. Using the postcode of residence, we assigned a Scottish Index of Multiple Deprivation (SIMD) score, SIMD quintile ( 0%-20% most deprived; 20%-40%, 40%-60%, 60%-80%, 80%-100% least deprived areas), geographical access score as well as the estimated travel time to the nearest general practitioner (GP) practice using either car or public transport for each patient. Population estimates were obtained from the General Register Office for Scotland. MAIN OUTCOME MEASURE: Serious ocular trauma requiring hospital admission. RESULTS: A total of 104 patients (85.6% male) were reported as being admitted with ocular trauma with a median age of 32 years (IQR 24-54). There was a trend for increasing incidence of serious ocular injury with increasing socioeconomic deprivation (p=0.034). Patients from the most deprived areas (SIMD: 0%-20%) were twice as likely to sustain ocular injury compared with those from the least deprived (SIMD: 80%-100%) areas (relative risk: 2.19, 95% CI 1.02 to 4.81). There was no significant difference in the drive/public transport time to GP practices across the SIMD quintiles. CONCLUSIONS: Increasing socioeconomic deprivation was associated with a higher incidence of serious ocular injury. Targeted interventions are needed to address inequality in eye healthcare in deprived areas.

The comparative relationships between locations of the papillary muscles and electrophysiologic QRS axis in patients with atrioventricular septal defect and common as opposed to separate orifices in the valve guarding the common atrioventricular junction.

BACKGROUND: Knowledge regarding factors that influence deviation of the QRS axis is important when seeking to differentiate between physiological and pathological changes. We hypothesised that, in contrast to those patients with an atrioventricular septal defect and common atrioventricular junction permitting only atrial shunting, those associated with ventricular shunting would show no relationship between the positions of the papillary muscles and the degree of the leftward deviation of the QRS axis. METHODS: We compared the positions of endocardial origin of the papillary muscles, and the frontal plane QRS axis, in patients with atrioventricular septal defects and common atrioventricular junction permitting exclusively atrial as opposed to atrial and ventricular shunting. RESULTS: We analysed 18 patients with atrial and ventricular shunting and 23 patients with exclusively atrial shunting. The correlation coefficient between the ratio of distances of the papillary muscles from the mid-septum and the amount of leftward deviation in the frontal plane QRS axis was 0.1 (p=0.4) in those with ventricular shunting and 0.26 (p=0.01) in those with exclusively atrial shunting. CONCLUSIONS: In contrast to patients with the so-called primum form of atrioventricular septal defect, in whom the locations of the papillary muscles correlate with the degree of QRS axis, such relationships are lacking in patients with defects permitting both atrial and ventricular shunting. It may be, therefore, that the presence of ventricular shunting and/or their younger age causes pressure overload, which negates the leftward QRS forces caused by the abnormally positioned papillary muscles.

Impact of socioeconomic deprivation on the development of diabetic retinopathy: a population-based, cross-sectional and longitudinal study over 12 years.

OBJECTIVE: To study the association between socioeconomic deprivation and prevalence of diabetic retinopathy (DR). DESIGN: Population-based, cross-sectional observational study and retrospective longitudinal analysis over 12 years. SETTING: Primary care, East of Scotland. METHODS: Outcome data from DR screening examinations (digital retinal photography) were collected from the Scottish regional diabetes electronic record from inception of database to December 2012. The overall Scottish Index of Multiple Deprivation (SIMD) 2012 score for each patient was obtained using their residential postcode. Multiple binary logistic regression was used to analyse the relationship between overall SIMD score and prevalence of DR, adjusting for other variables: age, gender, glycated haemoglobin, cholesterol levels and duration of disease. PRIMARY OUTCOME: Any retinopathy (R1 and above) in either eye. RESULTS: A total of 1861 patients with type 1 diabetes mellitus (DM) and 18,197 patients with type 2 DM were included in the study. Prevalence of DR in type 1 and type 2 DM were 56.3% and 25.5%, respectively. Increased prevalence of DR in type 1 DM was associated with higher overall SIMD score (p=0.002), with an OR for the most deprived relative to the least deprived of 2.40 (95% CI 1.36 to 4.27). In type 2 DM, the overall SIMD score was not significantly associated with increased prevalence of DR, with an OR for the most deprived relative to the least deprived of 0.85 (95% CI 0.71 to 1.02, p=0.07). CONCLUSIONS: Socioeconomic deprivation is associated with increased prevalence of DR in patients with type 1 DM and this occurs earlier. This highlights the need for targeted interventions to address inequalities in eye healthcare.