Nanomicelles empower natamycin in treating fungal keratitis: An in vitro, ex vivo and in vivo study

Fungal infections of cornea are important causes of blindness especially in developing nations with tropical climate. However, the challenges associated with current treatments are responsible for poor outcome. Natamycin is the only FDA-approved antifungal drug to treat fungal keratitis, but unfortunately due to its poor water solubility, it is available as suspension. The marketed suspension (5% Natamycin) has rapid precorneal clearance, poor corneal permeability, a higher frequency of administration, and corneal irritation due to undissolved suspended drug particles. In our study, we developed clear and stable natamycin-loaded nanomicelles (1% Natcel) to overcome the above challenges. We demonstrated that 1% Natcel could permeate the cornea better than 5% suspension. The developed 1% Natcel was able to provide sustained release for up to 24 h. Further, it was found to be biocompatible and also improved the mean residence time (MRT) than 5% suspension in tears. Therefore, the developed 1% Natcel could be a potential alternative treatment for fungal keratitis.

Tetraspanin CD9-derived peptides inhibit Pseudomonas aeruginosa corneal infection and aid in wound healing of corneal epithelial cells

Pseudomonas aeruginosa is a leading cause of corneal infection both within India and globally, often causing a loss of vision. Increasing antimicrobial resistance among the bacteria is making its treatment more difficult. Preventing initial bacterial adherence to the host membrane has been explored here to reduce infection of the cornea. Synthetic peptides derived from human tetraspanin CD9 have been shown to reduce infection in corneal cells both in vitro, ex vivo and in vivo. We found constitutive expression of CD9 in immortalized human corneal epithelial cells by flow cytometry and immunocytochemistry. The synthetic peptides derived from CD9 significantly reduced bacterial adherence to cultured corneal epithelial cells and ex vivo human cadaveric corneas as determined by colony forming units. The peptides also significantly reduced bacterial burden in a murine model of Pseudomonas keratitis and lowered the cellular infiltration in the corneal stroma. Additionally, the peptides aided corneal wound healing in uninfected C57BL/6 mice compared to control mice. These potential therapeutics had no effect on cell viability or proliferation of corneal epithelial cells and have the potential to be developed as an alternative therapeutic intervention.

Assessment of CT perfusion indices of the clinicoradiological response to anti-tubercular therapy in patients with intestinal tuberculosis

AIM

To explore the possibility of using a novel technique, CT perfusion imaging, to monitor the response to anti-tubercular therapy (ATT) in patients with intestinal tuberculosis.

MATERIALS AND METHODS

A prospective observational study was performed in adults with treatment naive-intestinal tuberculosis. Clinical, endoscopic, and conventional radiological findings of patients were compared at baseline and post-ATT. CT perfusion imaging was performed with recording of six perfusion parameters (blood flow, blood volume, mean transit time, time to peak, maximum peak intensity, and permeability/blood flow extraction).

RESULTS

Twenty-two patients (13 women, 59%) with a median age of 25 years were recruited. The terminal ileum and ileocaecal junction were the most frequent sites of involvement (59%), with multiple segments of the intestine being involved in 16 patients (73%). Median duration of ATT was 6 months (range 6-10 months). Complete clinical response was observed in 22/22 (100%) patients, endoscopic response in 12/12 (100%) patients, and radiological response in 10/13 (76%) patients. There was a significant decrease in mean blood flow, blood volume, maximum peak intensity, and an increase in mean transit time and time to peak on follow-up CT perfusion imaging performed after 6 months of ATT.

CONCLUSION

Significant alterations in CT perfusion parameters were demonstrated following treatment, consistent with a decline in inflammation and vascularity. CT perfusion imaging of the bowel is a novel means to assess the radiological response to ATT in intestinal tuberculosis, although at the cost of a higher dose of radiation exposure.

A survey of Asian Eye Institutions on perioperative antibiotic prophylaxis in cataract surgery

PURPOSE

To determine current institutional practice patterns for the use of perioperative antibiotics and other measures to prevent infection after cataract surgery in Asia.

METHODS

An online survey-based study of leading eye institutions in China, Hong Kong, India, Indonesia, Japan, Malaysia, Pakistan, Philippines, Singapore, South Korea, Taiwan, Thailand and Vietnam was conducted. The survey was administered to 26 representative key opinion leaders from prominent tertiary eye institutions that are also national academic teaching institutions in Asia. Survey responses were collated and anonymized during analysis.

RESULTS

All surveyed institutions used povidone iodine for the preoperative antiseptic preparation of the eye, with notable variations in the concentration of povidone iodine used for conjunctival sac instillation. Preoperative topical antibiotics were prescribed by 61.5% and 69.2% of institutions in low-risk and high-risk cases, respectively. Regarding the use of intra-operative antibiotics, 60.0% and 66.7% of institutions administered intracameral antibiotics in low-risk and high-risk patients, respectively. Postoperative topical antibiotics use patterns were generally very similar in low-risk and high-risk patients. Over half of the institutions (52.2% and 68.0% in low-risk and high-risk patients, respectively) also indicated prolonged postoperative use of topical antibiotics (> 2 weeks). Not all surveyed institutions had established policies/protocols for perioperative antibiotic use in cataract surgery, endophthalmitis surveillance, and/or a monitoring program for emerging antimicrobial resistance.

CONCLUSION

There are variations in antimicrobial prophylaxis approaches to preoperative, intra-operative and postoperative regimens in cataract surgery in Asia. More evidence-based research is needed to support the development of detailed guidelines for perioperative antibiotic prophylaxis to reduce postoperative infections.

Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510  GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510  GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02<x<0.08, with direct sensitivity to the sign of the gluon contribution.

Trachipleistophora hominis: molecular characterization of a rare pathogen causing microsporidial stromal keratitis

The authors report the clinical and microbiological findings of a unique case of stromal keratitis caused by a rare microsporidium, Trachipleistophora hominis. This case of stromal keratitis was in a 49-year-old male with a history of COVID-19 infection and diabetes mellitus. Corneal scraping specimens revealed numerous microsporidia spores upon microscopic examination. PCR of the corneal button revealed the presence of T. hominis infection, which could be controlled by penetrating keratoplasty surgery. The graft was clear with no recurrence of infection until the last follow-up 6 weeks postsurgery. This is the first case of human stromal keratitis caused by this organism in a post-COVID infection, confirmed by molecular diagnosis.

Unmasking of systemic lupus erythematosus in a patient with hemophagocytic lymphohistiocytosis- macrophage activation syndrome (HLA-MAS) and diffuse alveolar hemorrhage

Hemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome caused by macrophages and cytotoxic T cells with aberrant activation. The primary (genetic) form, which is caused by mutations that affect lymphocyte cytotoxicity and immune regulation, is most prevalent in children, whereas the secondary (acquired) form is prevalent in adults. Secondary HLH is commonly caused by infections or cancers, but it can also be caused by autoimmune disorders, in which case it is known as macrophage activation syndrome (MAS; or MAS-HLH). A 25-year-old female presented with a high-grade fever that lasted for two weeks. His laboratory results revealed pancytopenia, neutropenia, hypertriglyceridemia, hypofibrinogenemia, and hyperferritinemia. Based on the clinical presentation and laboratory findings, a provisional diagnosis of HLH has been made. A HLH protocol was utilized to treat the patient. During the course of hospitalization, systemic lupus erythematosus (SLE) was identified as the underlying cause. She improved dramatically after receiving an immunosuppressive regimen of etoposide, cyclosporine, and dexamethasone according to HLH protocol-2004 with individualized modifications. The clinician should be aware that HLH may be the initial manifestation of underlying SLE. Early diagnosis and aggressive, individualized treatment are the key to improving outcomes.

Association of Single-Nucleotide Polymorphisms in Interleukin Genes with Microbial Keratitis in a South Indian Population

BACKGROUND

To examine the relationship between single-nucleotide polymorphisms (SNPs) in interleukin (IL) genes and keratitis and its clinical manifestations.

METHODS

SNPs in IL1B, IL6, CXCL8, IL10, and IL12B were analysed. Differences in frequencies of alleles, genotypes and haplotypes between cases and controls as well as associations between SNPs and clinical variables were calculated by χ2 tests with odds ratios.

RESULTS

The minor homologous genotype in IL1B rs16944 (p = 0.036; odds ratio (OR) = 2.063, 95% confidence interval (CI): 1.048-4.061) and CXCL8 rs4073 (p = 0.041; OR = 0.463, 95% CI: 0.224-0.956) and the heterologous genotypes in IL6 rs1800795 (p = 0.046; OR = 0.563, 95% CI: 0.326-0.972) and IL12B rs2569254 (p = 0.0446; OR = 0.557, 95% CI: 0.314-0.989) or rs730691 (p = 0.0051; OR = 0.451, 95% CI: 0.260-0.784) were associated with keratitis. The minor genotype of rs16944 was associated with severe infection (p = 0.046). The heterologous genotype in rs2569254 was associated with hospital admission, photophobia, and mode of contact lens wear (p ≤ 0.041). The heterologous genotype in rs730691 was associated with blurred vision, discharge, anterior chamber reaction, and mode of wear (p ≤ 0.047).

CONCLUSIONS

This study demonstrates that SNPs in IL1B and CXCL8 are associated with risk of developing keratitis. The study also found relationships between SNPs and clinical measures of keratitis. The potential for ethnic differences in frequency of SNPs and their association with keratitis should be followed up using different populations.

Embracing technology in cataract surgical training - The way forward

While ophthalmology as a surgical branch itself has evolved technologically with newer instruments, techniques and procedures; ophthalmic surgical training appears to have stagnated in terms of how it is delivered and how trainees' learning and performance are assessed. This collaborative editorial attempts to identify the lacunae in ophthalmic residency training and highlight how technological tools such as surgical simulators can be incorporated into ophthalmic training even in limited-resource settings with good results.

Post-myocardial infarction late diastolic left ventricular blood flow energetics are independently associated with left ventricular remodeling

Background

Post-myocardial infarction (MI) left ventricular (LV) remodeling emerges as a compensatory mechanism and leads to complex pathophysiological changes in LV blood flow hemodynamics. The interplay, if any, between LV blood flow energetics and remodeling remains unknown. We hypothesized that LV blood flow energetics early after MI are independently related to the temporal changes in LV end-diastolic volume (LVEDV).

Methods

In this prospective cohort study, 69 patients with acute re-perfused ST-segment elevation MI (STEMI) were included. The patients underwent cardiovascular magnetic resonance (CMR) examination within 2 days of the index event and at 3-month. CMR examination included cine, late gadolinium enhancement, and whole-heart 4D flow acquisitions. LV volume-function, infarct size (indexed to body surface area), microvascular obstruction (MVO), mitral inflow, and 4D blood flow kinetic energy (KE) characteristics were obtained. LV mean and peak KEi (indexed to LVEDV) were quantified for all time parameters (entire cardiac cycle, during systole/diastole, at E- and A-waves).

Results

In univariable linear regression analysis, peak KEi (R-R interval), mean systolic KEi, A-wave KEi, MVO presence were all associated with the relative change (%) of LVEDV (p=0.03, p=0.01, p&lt;0.01, P=0.03, respectively). In multivariable linear regression analysis, A-wave KEi was identified as the only independent marker for association with the relative change of LVEDV (p=0.02). In another univariable linear regression analysis, A-wave KEi, infarct size, and MVO presence were all associated with the absolute change of LVEDV (p=0.03, p=0.04, p=0.04, respectively). In multivariable linear regression analysis, A-wave KEi was determined as the only independent marker for association with the absolute change of LVEDV (p=0.02). No significant association was observed between mitral inflow characteristics and relative and absolute change of LVEDV.

Conclusion

Late diastolic LV blood flow energetics early after acute MI are independently associated with both absolute and relative longitudinal changes in LVEDV and may provide incremental value over infarct and mitral inflow characteristics to be associated with post-MI LV remodeling.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): British Heart Foundation

S9.4a Ocular infections by melanized fungi Curvularia lunata and Lasiodiplodia theobromae: Antifungal susceptibility and clinical outcome

 

S9.4 Free oral presentations (late breaking), September 23, 2022, 4:45 PM - 6:15 PM

Purpose

To report antifungal susceptibility and clinical correlations in melanized fungal isolates of Curvularia lunata and Lasiodiplodia theobromae from ocular infections.

Methods

Antifungal susceptibility testing was performed by broth microdilution testing, following Clinical and Laboratory Standard Institute guidelines, of 17 C. lunata and 13 L. theobromae isolates from monomicrobial infections of microbial keratitis or fungal endophthalmitis patients. Isolates resistant to ≥2 classes of antifungals were considered as multidrug-resistant (MDR). The panel of antifungals tested were amphotericin B, natamycin, voriconazole, ketoconazole, fluconazole, itraconazole, posaconazole, and caspofungin.

Results

Voriconazole showed the highest susceptibility (83.3% isolates) followed by natamycin (80%), fluconazole (80%), itraconazole (76.7%), ketoconazole (70%), posaconazole, and caspofungin (66.7% each) and lastly amphotericin B (63.3%). For treatment, all patients received topical natamycin, and few received additional oral ketoconazole or intraocular voriconazole. MDR isolates led to the poorer clinical outcomes (P=.015) in patients. But natamycin resistance alone did not show unfavorable outcomes (P=.28), though this was the most frequent drug used topically in fungal ocular infections.

Conclusion

Melanized fungi causing ocular infections have varying susceptibility to different antifungal agents. Most effective drug as seen in vitro in our study, was voriconazole. Significant resistance to amphotericin B, which is the most common antifungal used in intravitreal injections, was noted. MDR isolates overall, had poorer clinical outcomes.

Early treatment of corneal abrasions and ulcers-estimating clinical and economic outcomes

Background

In low-and-middle income countries, corneal abrasions and ulcers are common and not always well managed. Previous studies showed better clinical outcomes with early presentation and treatment of minor abrasions, however, there have been no formal studies estimating the financial impact of early treatment of abrasions and ulcers compared to delayed treatment.

Methods

We used the LV Prasad Eye Institute's (LVPEI's) electronic health record system (eyeSmart) to estimate the impact of early presentation on clinical outcomes associated with abrasions and ulcers. 861 patients with corneal abrasion and 1821 patients with corneal ulcers were studied retrospectively, and 134 patients with corneal abrasion prospectively. A health economic model was constructed based on LVPEI cost data for a range of patient scenarios (from early presentation with abrasion to late presentation with ulcer).

Findings

Our findings suggest that delayed presentation of corneal abrasion results in poor clinical and economic outcomes due to increased risk of ulceration requiring more extensive surgical management, increasing associated costs to patients and the healthcare system. However, excellent results at low cost can be achieved by treatment of patients with early presentation of abrasions at village level health care centres.

Interpretation

Treatment of early minor corneal abrasions, particularly using local delivery of treatment, is effective clinically and economically. Future investment in making patients aware of the need to react promptly to corneal abrasions by accessing local healthcare resources (coupled with a campaign to prevent ulcerations occurring) will continue to improve clinical outcomes for patients at low cost and avoid complex and more expensive treatment to preserve sight.

Funding

This research was funded by the Medical Research Council, grant MR/S004688/1.

The quality of reporting in cardiac MRI artificial intelligence segmentation studies - a systematic review

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): This work was supported by an NIHR AI Award, AI_AWARD01706. This research was also funded in part, by the Wellcome Trust [Grant number 205188/Z/16/Z ].

Background

There has been a rapid increase in the number of Artificial Intelligence (AI) studies of cardiac MRI (CMR) segmentation. AI has huge potential to improve image analysis assessments. However, advancement and clinical translation in this field depend on researchers presenting their work in a transparent and reproducible manner.

Purpose

This systematic review aimed to evaluate the quality of reporting in AI studies involving CMR segmentation.

Methods

MEDLINE and EMBASE databases were searched for AI CMR segmentation studies on 18/11/2021. The flow of study inclusion is shown in Figure 1. Any AI method to segment any cardiac structure on CMR was eligible for inclusion. Each study was assessed for compliance with the Checklist for Artificial Intelligence in Medical Imaging (CLAIM).

Results

70 studies were included in the qualitative analysis. Studies were published between 2015 to 2021, with the majority (71%) published in 2020 and 2021. Most studies were performed in Europe (33%), China (27%) and the USA (26%). Short-axis sections were segmented in 70% of studies and most commonly included both ventricles (51%) or the left ventricle alone (30%). 20 different architecture implementations were represented. Figure 2 summarises the most relevant CLAIM domains to AI segmentation. The training sample eligibility criteria, demographics and clinical characteristics were not reported in 47% and 81% of studies, respectively. Ground truth annotations, source of the annotations and annotation tool were absent in 31%, 36% and 51% of studies respectively. Preprocessing steps and software libraries and packages used in training were not included in 27% and 24%. Details on the training approach including the number of models trained and method of selecting the final model were missing in 20% and 17% of the studies. Methods of validation or testing on external data, inter- and intra- rater variability and failure analysis were unreported in 57%, 63% and 74%, respectively.

Conclusion

This systematic review highlights important gaps in the AI literature of CMR studies. We identified key items missing in the dataset description, model development, validation and testing that limit the transparency, reproducibility and hence validity of published AI studies. This review may support closer adherence to established frameworks for reporting standards.

SGLT2 inhibitors in heart failure with preserved and reduced ejection fraction: a systematic review and meta-analysis

Funding Acknowledgements

Type of funding sources: None.

Background

Over the recent months, the scenery of the pharmacological treatment of heart failure has changed. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have become the protagonists, as trial after trial is revealing a prognostic benefit of their use for patients with heart failure (HF). While their clear advantage in heart failure with reduced ejection fraction (HFrEF) has resulted in the addition of SGLT2i in the most recent treatment guidelines 1, the magnitude of their impact in heart failure with preserved ejection fraction (HFpEF) is still debated. With the recent results of EMPEROR-Preserved trial shedding more light into this matter 2, concrete evidence is needed now more than ever to ascertain the role of SGLT2i in the management of HFpEF.

Aims

We performed a systematic review and meta-analysis to evaluate the role of SLGT2i in the management of patients with HF. More specifically, we performed a pre-specified subgroup analysis to assess the impact of this drug class in heart failure with reduced and preserved ejection fraction separately.

Methods

We conducted a systematic search of PubMed, Embase, Cochrane and Web of Science databases from inception to 15th of September. With the primary endpoint being hospitalisation for heart failure (HHF) or cardiovascular death (CVD), we identified 9,493 articles out of which 8 randomised controlled trials and 20,758 patients were included in the meta-analysis 2–9. The hazard ratios (HR) and 95% CI given in each study were used for the meta-analysis. A random-effects model with inverse-variance weights was used to combine the effect measures from all studies on a logarithmic scale. Statistical heterogeneity was assessed using the I² statistic. The statistical analyses were conducted using the Review Manager (RevMan) software (version 5.3. Copenhagen: The Nordic Cochrane Centre, The Cochrane Collaboration, 2014).

Results

The use of SGLT2i was associated with a significant reduction in HHF or CVD both for the patients with heart failure and EF&gt;40% (HR=0.78, 95%CI: 0.69, 0.87; I2 0%) and for the patients with heart failure and EF&lt;40% (HR=0.74, 95%CI: 0.68, 0.81; I2 0%), while for the total population SGLT2i reduced the risk of HHF or CV death by 25% (HR=0.75, 95%CI: 0.70, 0.81; I2 0%) (figure 1). Additionally, a prespecified subanalysis showed that in the specific cohort of patients with heart failure and EF&gt;50%, SGLT2i resulted in 23% lower risk of HHF or CV death (HR=0.77, 95%CI: 0.66, 0.91; I2 22%) (figure 2).

Conclusion

This meta-analysis provides robust evidence that SGLT2i appear to have a prognostic benefit across the spectrum of heart failure subgroups in terms of HHF or CV death. Further large-scale randomised trials examining the role of this drug class in the management of HFpEF would be extremely valuable and might transform the field of therapeutic strategies in this challenging clinical entity.

GENERATION AND USE OF FUNCTIONALISED HYDROGELS THAT CAN RAPIDLY SAMPLE INFECTED SURFACES

This paper outlined our method for developing polymer-linked contact lens type materials for rapid detection and differentiation of Gram-positive, Gram-negative bacteria and fungi in infected corneas. It can be applied to both model synthetic or ex-vivo corneal models and has been successfully trialed in an initial efficacy tested animal study. First a hydrogel substrate for the swab material is selected, we have demonstrated selective swabs using a glycerol monomethacrylate hydrogel. Alternatively any commercial material with carboxylic acid functional groups is suitable but risks nonspecific adhesion. This is then functionalised via use of N-hydroxysuccinimide reaction with amine groups on the specified highly branched polymer ligand (either individually gram negative, gram positive or fungal binding polymers or a combination of all three can be employed for desired sensing application). The hydrogel is then cut into swabs suitable for sampling, used, and then the presence of gram positive, game negative and fungi are disclosed by the sequential addition of dyes (fluorescent vancomycin, fluorescein isothiocyanate and calcofluor white).

In summary this method presents:

Method to produce glycerol monomethacrylate hydrogels to minimize nonspecific binding

Methods of attaching pathogen binding highly branched polymers to produce selective hydrogel swabs

Method for disclosing bound pathogens to this swab using sequential dye addition

Pythium insidiosum keratitis - A review

Pythium insidiosum is an oomycete and is also called “parafungus” as it closely mimics fungal keratitis. The last decade saw an unprecedented surge in Pythium keratitis cases, especially from Asia and India, probably due to growing research on the microorganism and improved diagnostic and treatment modalities. The clinical features such as subepithelial infiltrate, cotton wool-like fluffy stromal infiltrate, satellite lesions, corneal perforation, endoexudates, and anterior chamber hypopyon closely resemble fungus. The classical clinical features of Pythium that distinguish it from other microorganisms are reticular dots, tentacular projections, peripheral furrowing, and early limbal spread, which require a high index of clinical suspicion. Pythium also exhibits morphological and microbiological resemblance to fungus on routine smearing, revealing perpendicular or obtuse septate or aseptate branching hyphae. Culture on blood agar or any other nutritional agar is the gold standard for diagnosis. It grows as cream-colored white colonies with zoospores formation, further confirmed using the leaf incarnation method. Due to limited laboratory diagnostic modalities and delayed growth on culture, there was a recent shift toward various molecular diagnostic modalities such as polymerase chain reaction, confocal microscopy, ELISA, and immunodiffusion. As corneal scraping (10% KOH, Gram) reveals fungal hyphae, antifungals are started before the culture results are available. Recent in vitro molecular studies have suggested antibacterials as the first-line drugs in the form of 0.2% linezolid and 1% azithromycin. Early therapeutic keratoplasty is warranted in nonresolving cases. This review aims to describe the epidemiology, clinical features, laboratory and molecular diagnosis, and treatment of Pythium insidiosum keratitis.

Posterior Reversible Encephalopathy Syndrome: An Unusual Complication of Benzodiazepine Poisoning: A Case Report

Posterior Reversible Encephalopathy Syndrome (PRES), also known as Reversible Posterior Leukoencephalopathy Syndrome, presents with rapid onset symptoms, including headache, seizures, altered consciousness, and visual disturbance. It is seen most frequently in settings of acute hypertension and is usually related to eclampsia. Only a few cases in the literature described PRES syndrome following benzodiazepines. We present a young male with benzodiazepine poisoning brought to the hospital in a deep coma, hypoxia, acidosis, and shock. Diagnosis of PRES was made on history, clinical examination, and radiologic findings of symmetric bilateral hyperintensities on T2 weighted Magnetic Resonance Imaging (MRIs) representing vasogenic edema.

Posterior Reversible Encephalopathy Syndrome: An Unusual Complication of Benzodiazepine Poisoning: A Case Report

Posterior Reversible Encephalopathy Syndrome (PRES), also known as Reversible Posterior Leukoencephalopathy Syndrome, presents with rapid onset symptoms, including headache, seizures, altered consciousness, and visual disturbance. It is seen most frequently in settings of acute hypertension and is usually related to eclampsia. Only a few cases in the literature described PRES syndrome following benzodiazepines. We present a young male with benzodiazepine poisoning brought to the hospital in a deep coma, hypoxia, acidosis, and shock. Diagnosis of PRES was made on history, clinical examination, and radiologic findings of symmetric bilateral hyperintensities on T2 weighted Magnetic Resonance Imaging (MRIs) representing vasogenic edema.

Clinical Utility of COVID-19 Real Time-Polymerase Chain Reaction Testing of Ocular Tissues of Non-COVID-19 Cornea Donors Deemed Suitable for Corneal Retrieval and Transplantation

PURPOSE

The purpose of this study was to evaluate the prevalence of SARS-CoV-2 in human postmortem ocular tissues of asymptomatic donors and its implications on our eye banking protocols.

METHODS

The expression of SARS-CoV-2 RNA was assessed by reverse transcription-polymerase chain reaction in corneal rims and conjunctival tissues from 100 donors who were found suitable for transplantation as per the donor screening guidelines of the Global Alliance of Eye Bank Associations. The donor's clinical history and cause of death were assessed for secondary analysis.

RESULTS

Of 200 ocular tissues (100 corneal and 100 conjunctival) from the same 1 eye of 100 surgical-intended donors, between September 2020 and April 2021, the overall positivity rate for SARS-CoV-2 was ∼1% (2/200). Both the ocular samples that tested positive were conjunctival biopsies (2/100, 2%), whereas corneal samples were negative (0/100, 0%) in both donors. The causes of donor death were trauma in 51 donors, suicide in 33, cardiac arrest in 7, electric shock in 5, metabolic cause in 2, malignancy in 1, and snake bite in 1. None of the donors had a medical history suggestive of COVID infection or possible contact. None of the recipients from the donors were reported to have any systemic adverse event after keratoplasty until the follow-up of 6 weeks.

CONCLUSIONS

The overall prevalence of SARS-CoV-2 was 1% (2% for conjunctival and 0% for corneal samples, P value = 0.5) in the donors who were found suitable for cornea recovery and transplantation. The findings of exceptionally low positive rates in our samples validate the criticality of history-based donor screening and do not support the necessity of postmortem PCR testing as a criterion for procurement and subsequent use for corneal transplantation.

Microneedle scleral patch for minimally invasive delivery of triamcinolone to the posterior segment of eye

The delivery of therapeutics to the posterior segment of the eye is achieved by invasive procedures, including intravitreal injections and implants. The topically applied formulations would not permeate through different tissue barriers of the eye to reach the posterior segment. Here, we demonstrate the effectiveness of microneedle scleral patch in delivering the model molecule, triamcinolone acetonide, to the posterior segment of the eye. Microneedle scleral patch (MSP) and microneedle corneal patch (MCP) were fabricated through the micromolding technique using rapidly dissolvable polyvinylpyrrolidone. The patches containing 25 microneedles were characterized for physical and mechanical properties, drug loading and release behavior in vitro and ex vivo porcine eye globe model. The distribution of TA administered using MSP and MCP in different ocular tissues was evaluated in the rabbit eye model. The results showed that microneedles with 545 ± 8 µm length and 279 ± 26 µm width at the base in MSP penetrate the scleral membrane with the application of 0.35 ± 0.06 N force. The needles dissolved within 60 s after insertion in the corneal and scleral tissue. The 5 min application of MSP showed a significantly (p < 0.05) greater TA disposition in the vitreous humor and choroid-retinal complex in excised porcine eye globe compared with MCP and TA nanosuspension eye drops. In rabbit model studies, the TA concentration was greatest in the choroid-retinal complex and sclera after administration through intravitreal injection and MSP, respectively. The TA disposition in the sclera was significantly (p < 0.05) greater after MSP application compared with intravitreal injection and MCP application for up to 24 h. MSP application provided a greater safety score compared with intravitreal injection. In conclusion, MSP can be developed as a minimally invasive drug delivery system to target the posterior segment of the eye.

Chronic groin pain in Desarda versus Lichtenstein hernia repair - a randomised controlled study

BACKGROUND: Chronic pain after inguinal hernia repair is a common complication. This study compared the difference between Desarda repair and Lichtenstein repair for inguinal hernia in chronic groin pain. METHODS: One hundred patients with unilateral uncomplicated inguinal hernia were randomised to either Desarda repair (n = 50) or Lichtenstein repair (n = 50) under local anaesthesia and were evaluated for pain postoperatively. Operative time, surgical complications, time to return to normal gait and work, and overall patient satisfaction were recorded. The patient was blinded to the procedure. Any pain at three months (numerical rating scale 1 or more) was considered chronic pain. RESULTS: Mean operation time was approximately 5 minutes less for Desarda (p = 0.33). There was no significant difference in terms of pain level postoperatively between Lichtenstein and Desarda groups. Twenty-two (44%) patients in the Lichtenstein group had chronic pain, and twenty-one (45.7%) patients had chronic pain in the Desarda group (p = 0.871). No significant difference was observed in haematoma formation, wound infection, recurrence rate, seroma, or foreign body sensation. The mean time for patients to return to normal gait was approximately 0.5 day earlier for the Desarda group (p = 0.29). The mean time for patients to return to normal work was comparable (p = 0.99). Desarda group had a slightly higher satisfaction rate than the Lichtenstein group (9.1%). CONCLUSION: Desarda repair is not inferior to Lichtenstein repair in the short-term concerning complications or pain.

Efficacy of voriconazole and amphotericin B in corneal preservative media

Purpose:

To evaluate the efficacy of voriconazole and amphotericin B in McCarey–Kaufman (MK) media.

Methods:

MK media vials were supplemented with either voriconazole at 1, 2, 20, 50, 100 μg/mL or amphotericin B at 0.5, 1, 2, 10, 20 μg/mL. The standard inoculum of the American Type Culture Collection (ATCC) strain of Candida albicans, Aspergillus flavus, and Fusarium keratinoplasticum was added to the set of vials. The efficacy outcomes were calculated as ‘viable fungal colony counts’ determined from the samples taken on Days 0 and 4. MK media containing fungal inoculum but without antifungal supplements were used as control.

Results:

In the voriconazole arm, on Day 4, a reduction in the colony count was observed for Candida albicans (1 μg/mL, 36%; 100 μg/mL, 100%), Aspergillus flavus (1 μg/mL, 53.8%; 100 μg/mL, 80.4%), and Fusarium keratinoplasticum (1 μg/mL, 39.0%; 100 μg/mL, 72.2%). Similarly, in the amphotericin B arm, on Day 4, a reduction in the colony count was observed for Candida albicans (0.5 μg/mL; 99.9%; 20 μg/mL, 100%), Aspergillus flavus (0.5 μg/mL, 65.2%; 20 μg/mL, 84.8%), and Fusarium keratinoplasticum (0.5 μg/mL, 90.1%; 20 μg/mL, 100%).

Conclusion:

Compared to voriconazole, the addition of amphotericin B significantly reduces fungal contamination in MK media.

Evaluation of ligand modified poly (N-Isopropyl acrylamide) hydrogel for etiological diagnosis of corneal infection

Corneal ulcers, a leading cause of blindness in the developing world are treated inappropriately without prior microbiology assessment because of issues related to availability or cost of accessing these services.

In this work we aimed to develop a device for identifying the presence of Gram-positive or Gram-negative bacteria or fungi that can be used by someone without the need for a microbiology laboratory. Working with branched poly (N-isopropyl acrylamide) (PNIPAM) tagged with Vancomycin, Polymyxin B, or Amphotericin B to bind Gram-positive bacteria, Gram-negative bacteria and fungi respectively, grafted onto a single hydrogel we demonstrated specific binding of the organisms. The limit of detection of the microbes by these polymers was between 10 and 4 organisms per high power field (100X) for bacteria and fungi binding polymers respectively. Using ex vivo and animal cornea infection models infected with bacteria, fungi or both we than demonstrated that the triple functionalised hydrogel could pick up all 3 organisms after being in place for 30 min. To confirm the presence of bacteria and fungi we used conventional microbiology techniques and fluorescently labelled ligands or dyes.

While we need to develop an easy-to-use either a colorimetric or an imaging system to detect the fluorescent signals, this study presents for the first time a simple to use hydrogel system, which can be applied to infected eyes and specifically binds different classes of infecting agents within a short space of time. Ultimately this diagnostic system will not require trained microbiologists for its use and will be used at the point-of-care.

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Functionalised branched Poly N-isopropyl acrylamide binds corneal ulcer causing microorganisms.

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The functionalised polymers demonstrated specific binding to gram positive, gram negative and fungi.

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Grafting three different polymers on a single hydrogel retained this specific binding for microorganisms.

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Triple functionalised hydrogels were effective in picking up microorganisms in ex-vivo and animal cornea infection models.

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Application for a duration of 30 min was sufficient to pick up enough organisms for subsequent identification.

Application of Trypan Blue Stain in the Microbiological Diagnosis of Infectious Keratitis-A Case Series

PURPOSE

The purpose of this study was to report 3 cases of microbial keratitis, wherein trypan blue staining was used to aid the microbiological diagnosis of fungal keratitis and Pythium keratitis in a rural setup.

METHODS

Three consecutive patients who presented with a diagnosis of infectious keratitis underwent corneal scraping, and the smears were assessed using trypan blue stain and potassium hydroxide (KOH) mount.

RESULTS

Of the 3 cases, the first 2 cases showed septate fungal filaments in trypan blue-stained preparation and KOH mount. Case 3 showed the presence of broad aseptate filaments with ribbon-like folds on both KOH mount and trypan blue stain, consistent with the diagnosis of Pythium keratitis. The first 2 cases improved with topical and systemic antifungals. Case 1 healed with scarring at 7 weeks with improvement in best-corrected visual acuity (BCVA) to 20/60. Case 2 healed within 2 weeks, and BCVA improved to 20/40. Case 3 received topical linezolid (0.2%), azithromycin eye ointment, and oral azithromycin. At 5 weeks the infection decreased but thinning was noted, which necessitated tissue adhesive and bandage contact lens application. Scarring was noted at 10 weeks, and BCVA improved to 20/40.

CONCLUSIONS

In this case series, trypan blue staining showed promising results in the easy identification of aseptate and septate fungal elements. This is the first case series showing the utility of this stain in the management of microbial keratitis.

Year one of COVID-19 pandemic in India: Effect of lockdown and unlock on trends in keratoplasty at a tertiary eye centre

PURPOSE

To describe the impact of lockdown and unlock phases of the COVID-19 pandemic on keratoplasty trends at a tertiary eye care center in India.

METHODS

This cross-sectional hospital-based study included 6,277 patients presenting between March 25, 2017 and March 31, 2021. The data of the patients who underwent keratoplasty during the lockdown and unlock phases were compared with the respective periods in the previous three years before COVID-19.

RESULTS

During the year one of pandemic, there was a 29.46% decline in the total number of keratoplasty performed at the institute compared to previous year's annual numbers. The patients undergoing keratoplasty decreased by 90.28% (28/288) of pre-COVID-19 volumes during the lockdown phase. This was mainly because of a 40.6% reduction in the proportion of patients requiring interstate travel. There was complete recovery in the number of patients undergoing keratoplasty to 129.27% (184/142) of pre-COVID-19 volumes by March 2021. This gradual incremental trend was seen across all types of keratoplasty in Descemet stripping endothelial keratoplasty (135.29%), penetrating keratoplasty (117.6%), therapeutic keratoplasty (122.22%), anterior lamellar keratoplasty (150%), and Descemet membrane endothelial keratoplasty (141.18%) by March 2021 with the gradual ease of lockdown regulations. The eye bank affiliated to the institute saw a 55.44% decline in donor cornea collection and an increase in utilization rate from 58.12% in previous years to 83.78% in year one of the pandemic. The overall eye bank donor cornea collection recovered to 86.96% (627/721) and tissue utilization increased by 109.99% (455/414) by March 2021.

CONCLUSION

The first year of the COVID-19 pandemic saw an overall reduction of 29.46% of the patients undergoing keratoplasty at the institute. There was a gradual and incremental increase in all types of keratoplasty in the unlock phase, which surpassed the preceding years' monthly numbers in February and March.

Changing trend in the morphology of cataracts at a tertiary eye care centre in South India due to COVID-19-pandemic related national lockdown

Purpose:

To study the changing trends in the morphology of cataracts at a tertiary eye care center in South India due to COVID-19 pandemic-related national lockdown.

Methods:

A retrospective study conducted at a tertiary eye care center in Andhra Pradesh state of South India, which included 1724 patients (1753 eyes) who underwent cataract surgery at our center during April 2019–July 2019 (1298 eyes of 1271 patients) and April 2020–July 2020 (455 eyes of 453 patients). Factors studied included preoperative lens status, associated phacodonesis or subluxation, pupil size, other eye lens status, associated retinal problems, glaucoma, and complications during surgery. Postoperative uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), corneal clarity, intraocular pressure (IOP), and disc status at postoperative day 1, 1 week, and 1-month visits were compared.

Results:

A significantly lower proportion of nuclear sclerosis (decreased from 83.2% in last year before lockdown to 55.2% during lockdown) and significantly higher proportions of mature, brown, or black cataract and phacomorphic, phacolytic, or Morgagnian cataract (increased from 15.5% in last year before lockdown to 43.8% during lockdown) were observed. The proportion of small-incision cataract surgery decreased significantly (from 63.2% to 57.4%), whereas the proportion of phacoemulsification increased significantly (from 35.9% to 41.5%) during lockdown as compared to last year. A significantly higher proportion of eyes with small pupils and association with retinal pathology were also observed during the lockdown.

Conclusion:

During the national lockdown, there was a shift from nuclear sclerosis grade toward mature, brown, black grade of cataracts. In addition, the proportion of small-incision cataract surgery decreased significantly whereas the proportion of phacoemulsification increased significantly during the lockdown. More number of cataracts with small pupils and associated retinal pathology were observed during the lockdown.

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p^{↑}+p Collisions at sqrt[s]=200 GeV

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200  GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.

Left ventricular blood flow energetics after acute ST-segment elevation myocardial infarction associate with left ventricular remodeling

Background

Myocardial infarction (MI) leads to complex changes in left ventricular (LV) haemodynamics. It remains unknown how four-dimensional (4D) acute changes in LV blood flow kinetic energy (KE) affect LV remodeling. We hypothesized that LV blood flow energetics are independently associated with adverse LV-remodeling.

Methods

In total, 69 revascularised ST-segment elevation MI patients were enrolled. All patients underwent cardiovascular magnetic resonance (CMR) examination within 2 days of the index event and at 3-month. CMR examination included cine, late gadolinium enhancement, and whole-heart 4D flow acquisitions. CMR analysis included: LV volumes, function, infarct size (indexed to body surface area), microvascular obstruction (MVO), two-dimensional, retrospective valve tracking derived mitral inflow metrics, and 4D blood flow KE components (Fig. 1). Adverse LV-remodeling was defined and categorized according to increase in LV end-diastolic volume: 10% (mild), 15% (moderate), and 20% (severe).

Results

Twenty-four patients (35%) developed mild, 17 patients (25%) moderate, 11 patients (16%) severe LV remodeling. Demographics and clinical history were comparable between patients with/without LV remodeling. In univariable logistic regression analysis, A-wave KE was associated with mild, moderate, and severe LV remodeling (p=0.03, p=0.02, p=0.02, respectively), whereas infarct size was associated with only mild LV remodeling (p=0.02). In multivariable logistic regression analysis, whilst the infarct size and A-wave KE were identified as independent markers for mild LV remodeling (p=0.03, p=0.09, respectively), A-wave KE was the only independent marker regarding moderate and severe LV remodeling (both, p&lt;0.01). In ROC analysis for A-wave KE to be associated with the presence of adverse LV remodeling, the area under the curve was 0.67 for mild (p=0.02), 0.70 for moderate (p=0.01), 0.71 for severe (p=0.03) LV remodeling.

Conclusion

In patients with STEMI, LV hemodynamics assessment by LV blood flow KE demonstrated an incremental value to predict adverse LV-remodeling. A-wave KE early after acute MI had an independent effect on adverse LV remodeling.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): This work was supported by the British Heart Foundation [FS/10/62/28409 to S.P.] and Dutch Technology Foundation (STW), project number 11626 (JW, ME).

High interstudy repeatability of automatic deep learnt biventricular CMR measurements

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Wellcome Trust (UK), NIHR (UK)

Introduction

Cardiac magnetic resonance (CMR) measurements have significant diagnostic and prognostic value. Accurate and repeatable measurements are essential to assess disease severity, evaluate therapy response and monitor disease progression. Deep learning approaches have shown promise for automatic left ventricular (LV) segmentation on CMR, however fully automatic right ventricular (RV) segmentation remains challenging. We aimed to develop a biventricular automatic contouring model and evaluate the interstudy repeatability of the model in a prospectively recruited cohort.

Methods

A deep learning CMR contouring model was developed in a retrospective multi-vendor (Siemens and General Electric), multi-pathology cohort of patients, predominantly with heart failure, pulmonary hypertension and lung diseases (n = 400, ASPIRE registry). Biventricular segmentations were made on all CMR studies across cardiac phases. To test the accuracy of the automatic segmentation, 30 ASPIRE CMRs were segmented independently by two CMR experts. Each segmentation was compared to the automatic contouring with agreement assessed using the Dice similarity coefficient (DSC). 

A prospective validation cohort of 46 subjects (10 healthy volunteers and 36 patients with pulmonary hypertension) were recruited to assess interstudy agreement of automatic and manual CMR assessments. Two CMR studies were performed during separate sessions on the same day. Interstudy repeatability was assessed using intraclass correlation coefficient (ICC) and Bland-Altman plots. 

Results

DSC showed high agreement (figure 1) comparing automatic and expert CMR readers, with minimal bias towards either CMR expert. The scan-scan repeatability CMR measurements were higher for all automatic RV measurements (ICC 0.89 to 0.98) compared to manual RV measurements (0.78 to 0.98). LV automatic and manual measurements were similarly repeatable (figure 2). Bland-Altman plots showed strong agreement with small mean differences between the scan-scan measurements (figure 2).

Conclusion

Fully automatic biventricular short-axis segmentations are comparable with expert manual segmentations, and have shown excellent interstudy repeatability.

Left ventricular four-dimensional blood flow energetics and vorticity in chronic myocardial infarction patients with/without left ventricular thrombus

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): The British Heart Foundation [FS/10/62/28409] and Dutch ZonMw [104003001].

Background

Left ventricular thrombus (LVT) formation is a frequent and serious complication of myocardial infarction (MI). How global LV flow characteristics are related to this phenomenon is yet uncertain. In this study, we investigated LV flow differences using 4D flow cardiovascular magnetic resonance (CMR) between chronic MI patients with LVT [MI-LVT(+)] and without LVT [MI-LVT(-)], and healthy controls.

Methods

In this prospective cohort study, the 4D flow CMR data were acquired in 19 chronic MI patients (MI-LVT(+), n= 9 and MI-LVT(-), n= 10) and 9 age-matched controls. All included subjects were in sinus rhythm. The following LV flow parameters were obtained: LV flow components (direct, retained, delayed, residual), mean and peak KE values (indexed to instantaneous LV volume), mean and peak vorticity values, and diastolic vortex ring properties (position, orientation, shape).

Results

The MI patients demonstrated a significantly larger amount of delayed and residual flow, and a smaller amount of direct flow compared to controls (p = 0.02, p = 0.03, and p &lt; 0.001, respectively). The MI-LVT(+) patients demonstrated numerically increased residual flow and reduced retained and direct flow in comparison to MI-LVT(-) patients. Systolic mean and peak LV blood flow KE values were significantly lower in MI patients compared to controls (p = 0.04, p = 0.03, respectively). Overall, the mean and peak LV vorticity values were significantly lower in MI patients compared to controls. The mean vorticity at the basal level was significantly higher in MI-LVT(+) than in MI-LVT(-) patients (p &lt; 0.01). The vortex ring core during E-wave in MI-LVT(-) group was located closer to the mitral annulus and in a less tilted orientation to the LV compared to MI-LVT(+) group (p = 0.05, p &lt; 0.01, respectively).

Conclusion

Chronic MI patients with LVT express a different distribution of LV flow components, irregular vorticity vector fields, and altered diastolic vortex ring geometric properties as assessed by 4D flow CMR. Larger prospective studies are warranted to further evaluate these initial observations.

Fully automated CMR derived stroke volume correlates with right heart catheter measurements in patients with suspected pulmonary hypertension

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): Welcome Trust (UK), NIHR (UK)

Introduction

Cardiac magnetic resonance (CMR) assessment plays a significant role in the diagnosis, prognosis and monitoring of patients with pulmonary hypertension (PH). We developed a deep learning model to automatically generate biventricular contours and validated its result in a prospective cohort of patients with suspected PH who underwent right heart catheterization (RHC).

Methods

A deep learning CMR contouring model was developed in a retrospective multi-vendor (Siemens and General Electric), multi-pathology cohort of patients, predominantly with heart failure, lung disease and PH (n = 400, ASPIRE registry). Biventricular segmentations were made on all CMR studies across cardiac phases. A prospective validation cohort of 102 suspected PH patients was recruited and they had RHC within 24 hours  of the CMR. To test the accuracy of the automatic segmentation, the RHC-thermodilution and CMR-derived measures of stroke volume (SV) were compared for manual and automated measurements. 

Results

The mean and standard deviation for the derived SV was 59 ml ± 21 measured by RHC and 75 ml ± 25 for automated and 79 ml ± 26 for manual CMR measurements. Automatic and manual CMR measurement correlated strongly with RHC derived SV; 0.73, 95% CI [0.62, 0.81] and 0.78, 95% CI [0.69, 0.85], respectively (figure 1).  The agreement between automatic and manual SV was high; interclass correlation coefficient (ICC) = 0.88, 95% CI [0.83, 0.92] and Bland-Altman plots showed a narrow spread of mean differences between manual and automatic measurements (figure 2).

Conclusion

In a prospective cohort, fully automatic CMR assessments corresponded accurately to invasive hemodynamics performed within 24 hours of a CMR study.

Hospital Cornea Retrieval Programme in a startup eye bank - A retrospective analysis and lessons learned

Purpose:

This study aimed to share our experience in the hospital cornea retrieval program as a new eye bank.

Methods:

This was a retrospective study conducted in a tertiary care institute from August 26, 2019 to March 22, 2020. The medical and eye bank records were analyzed for hospital mortality, mortuary records, and donors approached. The corneal collection was divided between Voluntary (received from voluntary calls), HCRP (cornea received from hospital deaths), and Medico-Legal Cases (received from MLC deaths in hospital) to see the trend of donation and utilization over time.

Results:

During the study period, 154 corneas (77 pairs) were collected. The HCRP provided a major source of corneas 58.4% (90 corneas) as compared to voluntary 19.5% (30 corneas) and MLC 22.1%(34 corneas). There were younger tissues in MLC than HCRP donors, and older tissues in Voluntary donors, and the difference was statistically significant. There was no significant difference in the quality of optical grade tissues and the utilization of corneas for transplants between the three groups. Post hoc analysis showed more non-optical tissues in the voluntary donations (P = 0.004), maximum donors with medical contraindications in the HCRP group (P = 0.001), and time-lapse in corneal retrieval in MLC cases (P = 0.0001). Of these 154 corneas, 78 (50.6%) were assessed as suitable for transplantation, of which 59 (75.6%) tissues were optical grade tissues. The overall utilization was 39.6%.

Conclusion:

HCRP is indeed challenging for a new eye bank, but proper understanding and implementing strategies may help for good utilization of tissues.

Impact of COVID-19 related national lockdown on care of corneal transplantation patients at a tertiary eye care centre in India

Purpose

To study impact of COVID-19 related national lockdown on care of corneal transplantation patients at a tertiary eye centre in Andhra Pradesh state of South India.

Methods

Cross-sectional questionnaire-based study conducted at tertiary eye care centre in Andhra Pradesh state of South India, included 109 patients who underwent keratoplasty(full thickness or partial thickness) at our centre and who came for follow-up visit after lockdown. Factors such as type, indication, number of keratoplasties in the operated eye, and unusual clinical outcomes identified during visit after the lockdown, were studied. Uncorrected visual acuity, best corrected visual acuity, clarity of graft, graft-host junction apposition, intactness of sutures, intraocular pressure and disc status were compared on visits made before and after lockdown.

Results

During lockdown, 77.1% patients were properly using medications that was significantly (P = 0.0003) lower than that of before the lockdown (90.8%). After the lockdown, 82.3% patients were using medications properly that was comparable (P = 0.11) to that of during the lockdown (77.1%). The proportion of eyes with clear grafts and intact sutures decreased significantly after lockdown. The unusual outcomes observed after the lockdown were graft failure (36.7%), graft edema (11%), graft infiltrate(5.5%), phthysis bulbi (1.85%) and edematous graft cleared in eyes 3.7% eyes.

Conclusion

We noted significant drop in usage of medications from 91% before lockdown to 77% during lockdown and maintained at 83% after lockdown. Edematous grafts increased from 41% before lockdown to 54% after the lockdown. Intactness of sutures decreased from 82% before lockdown to 69% after lockdown.

Keratitis following laser refractive surgery: Clinical spectrum, prevention and management

Laser refractive surgery (LRS) is one of the most demanding areas of ophthalmic surgery and high level of precision is required to meet outcome expectations of patients. Post-operative recovery is of vital importance. Keratitis occurring after LRS can delay visual recovery. Both surface ablations [Photorefractive keratectomy (PRK)] as well as flap procedures [Laser in-situ keratomileusis (LASIK)/Small incision lenticule extraction] are prone to this complication. Reported incidence of post-LRS infectious keratitis is between 0% and 1.5%. The rate of infections after PRK seems to be higher than that after LASIK. Staphylococci, streptococci, and mycobacteria are the common etiological organisms. About 50–60% of patients present within the first week of surgery. Of the non-infectious keratitis, diffuse lamellar keratitis (DLK) is the most common with reported rates between 0.4% and 4.38%. The incidence of DLK seems to be higher with femtosecond LASIK than with microkeratome LASIK. A lot of stress is laid on prevention of this complication through proper case selection, asepsis, and use of improved protocols. Once keratitis develops, the right approach can help resolve this condition quickly. In cases of suspected microbial keratitis, laboratory identification of the organism is important. Most lesions resolve with medical management alone. Interface irrigation, flap amputation, collagen cross-linking and therapeutic penetrating keratoplasty (TPK) are reserved for severe/non-resolving cases. About 50–75% of all infectious keratitis cases post LRS resolve with a final vision of 20/40 or greater. Improved awareness, early diagnosis, and appropriate intervention can help limit the damage to cornea and preserve vision.

Diagnostic accuracy of 4D flow MRI comparing 2mm3 and 3mm3 spatial resolution

Funding Acknowledgements

Type of funding sources: Public Institution(s). Main funding source(s): National Institute for Health Research, UK University of Leeds

Background

Cardiac magnetic resonance (CMR) examinations requiring repeated breath-holds are challenging in younger patients. While 4-dimensional phase-contrast (4D flow) CMR does not require breath-holds, acquisition has been lengthy. Therefore to date spatial resolution has been influenced mainly by scan length. With accelerated sequences becoming available, higher spatial resolution is becoming clinically feasible.

Purpose

We therefore evaluated the minimum spatial resolution in 4D flow CMR necessary for accurate clinical assessment.

Methods

Ten healthy volunteers (mean age 24.8 years) underwent cardiac examinations on a 3T scanner using a 4D Flow prototype sequence at 2x2x2mm3 (4DFlow2) and 3x3x3mm3 (4DFlow3) spatial resolution. Net forward flow (FF) and peak velocity (PV) using valve tracking were calculated with commercially available software and kinetic energy (KE) in the left ventricle (LV) was analysed using a research tool. Bland-Altman analysis was used for statistical assessment and is reported as bias ± limits of agreement.

Results

Aortic valve flow metrics were similar in 4DFlow2 (FF 94ml; PV 133cm/s) and 4DFlow3 (FF 95ml; PV 130cm/s), and both showed good agreement with 2D PC MRI (FF 93ml, Bland-Altman:1.6 ± 9.7 and 2.2 ± 13.5, respectively). Similar results were obtained for pulmonary valve flow (FF 138cm/s; Bland-Altman:4.7 ± 15.1 and 8.1 ± 18.2, respectively). Branch pulmonary artery (PA) FF showed good agreement with the main PA FF in 2D and 4DFlow2 (Bland-Altman:1.1 ± 15.9 and 1.1 ± 10.6, respectively), but not in 4DFlow3 (Bland-Altman:1.1 ± 32.5). Global LV KE measured by 4DFlow3 was on average 12% lower compared to 4DFlow2, whereas maximum systolic LV KE was similar in both acquisition methods.

Conclusions

3mm3 spatial resolution appears to be sufficient for clinical evaluation of aortic and pulmonary valves. Smaller vessels such as branch pulmonary arteries require higher resolution for accurate assessment. While no gold standard is available for kinetic energy assessment, our results suggest that some parameters LV energetic assessment is spatial resolution sensitive. Differences in SNR might also contribute to the differing results.

Abstract Figure. Bland-Altman plots for 4D flow MRI

Risk Factors for Contact Lens-Related Microbial Keratitis and Associated Vision Loss in a South Indian Population

OBJECTIVES

To identify risk factors associated with contact lens-related microbial keratitis (CL-MK) and subsequent vision loss in a south Indian population.

METHODS

A retrospective study of medical records at the LV Prasad Eye Institute in Hyderabad, India, of patients diagnosed with CL-MK and of controls who had no history of corneal inflammation during contact lens wear was undertaken. Variables such as demographic data, contact lens wear details, duration of the event, visual acuity, epithelial defect and infiltrate size, and microbiology of the cornea during the event were collected. Differences between cases and controls were analyzed using parametric and nonparametric tests. Logistic regression was used to calculate the odds ratio (OR) and associated 95% confidence intervals in univariate and multivariate analyses for cases vs. controls and for factors associated with vision loss.

RESULTS

One hundred sixty-seven cases of CL-MK and 153 controls were included in the analyses. Risk factors associated with the greatest increased OR for CL-related MK were: being in professional employment vs. a student (OR=3.9), disposing lenses yearly versus monthly or biweekly (OR=2.2), and any overnight wear (OR=2.8). Risk factors associated with vision loss were: high myopia (OR=3.6), severe vs. mild severity (OR=16.0), and hypopyon (OR=4.3).

CONCLUSIONS

Identification of these risk factors may help inform safe contact lens wear habits and management strategies.

Sol-Gel Nanocomposite Coatings for Preventing Biofilm Formation on Contact Lens Cases

Purpose

To evaluate the efficacy of a nanosilver-based sol–gel coating in preventing biofilm formation on contact lens cases.

Methods

An organic–inorganic hybrid silica–zirconia sol formulation with immobilized silver nanoparticles was deposited on contact lens case coupons. The coated and uncoated coupons were subjected to biofilm formation to Gram-negative and Gram-positive keratitis isolates and ATCC strains using a standard protocol. The biofilms were evaluated using crystal violet, MTT assay, and scanning electron microscope (SEM) examination. The duration of efficacy of the coating was evaluated by exposing the coated and uncoated coupons to a multipurpose lens cleaning solution for various durations up to 30 days and comparing their biofilm characteristics. The cytotoxicity of the coated surface was assessed using cell culture studies.

Results

Cross-hatch tests and SEM confirmed the presence of a uniform, well-adhered coating on the surface. The coating resulted in a nearly 95% reduction in biofilm formation of the tested bacteria and was effective despite exposures of up to 30 days to a multipurpose lens cleaning solution. The coating did not exhibit cytotoxicity to human corneal epithelial cells.

Conclusions

The silver nanoparticle-based coating exhibits a good antibiofilm property for both Gram-negative bacilli and Gram-positive cocci and is promising for commercial use in preventing contact lens-related infections.

Translational Relevance

Biofilm formation on lens cases continues to be an important concern. The proposed coating will help reduce such formations, thus reducing the risk of lens-associated microbial keratitis.

Response of L V Prasad Eye Institute to COVID-19 outbreak in India: experience at its tertiary eye care centre and adoption to its Eye Health Pyramid

AIM

To summarize the experience of response to COVID-19 outbreak at a tertiary eye care institute and its network of health facilities in India.

METHODS

Our responses are based on the principles of social distancing, hand hygiene, respiratory etiquettes, surface disinfection protocol, and rational use of appropriate personal protective equipment (PPE). We describe our response in terms of administrative controls, clinical protocols, staff protection, environmental controls, and social distancing measures. We also discuss our communication strategies and monitoring systems, to ensure compliance to protocols.

RESULTS

Administrative control is mainly related to formation of task force and its functions. Clinical protocols are related to patient triaging methods and clinical examination guidelines in Outpatient, Inpatient and Operating Room. Staff protection is focused on training staff on the protocols to be followed in hospital as well as at home, and use of PPE. Environmental protocol is focused on cleaning and disinfectant methods to be used in the hospital. In addition, there are systems for communication as well as monitoring compliance to protocols.

CONCLUSION

We hope that these protocols and our experience would help the ophthalmic community globally and serve as a guide to protect ophthalmologists and ophthalmic care personnel, and their patients across the world.

Branched amphotericin functional poly(N-isopropyl acrylamide): an antifungal polymer

Branched poly(N-isopropylacrylamide) was functionalized with Amphotericin B (AmB) at the chain ends to produce an antifungal material. The polymer showed antifungal properties against AmB-sensitive strains of Candida albicans, Fusarium keratoplasticum and Aspergillus flavus (minimal inhibitory concentration ranged from 5 to 500 µg ml^-1) but was not effective against an AmB resistant strain of C. albicans nor against Candida tropicalis. The polymer end groups bound to the AmB target, ergosterol, and the fluorescence spectrum of a dye used as a solvatochromic probe, Nile red, was blue shifted indicating that segments of the polymer became desolvated on binding. The polymer was less toxic to corneal and renal epithelial cells and explanted corneal tissue than the free drug. Also, the polymer did not induce reactive oxygen species release from peripheral blood mononuclear cells, nor did it cause a substantial release of the proinflammatory cytokines, tumour necrosis factor-α and interleukin-1β (at 0.5 mg ml^-1).