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Aim: To investigate the role of interleukin-17 in ocular surface and corneal disease. Ocular surface and corneal disease is a leading cause of blindness and is an ongoing challenge for the public health sector to implement effective therapies. The majority of cells in corneal lesions are derived primarily from neutrophils that induce inflammatory events that lead to tissue damage. One of the key pro-inflammatory cytokines is IL-17, and it has been investigated in order to facilitate the understanding of the pathogenesis of ocular surface lesion development. Method: A review of the literature was performed through a systematic approach. Results: IL-17 has been shown to exacerbate dry eye disease, viral and bacterial keratitis lesion severity, although it was found to be protective for Acanthamoeba. Antibodies developed to neutralize IL-17 have shown some promise in reducing the severity of some diseases. Conclusion: IL-17 plays a role in the pathogenesis of ocular surface and corneal disease and targeting this cytokine may provide a useful treatment option in the future. [ABSTRACT FROM AUTHOR]

Contact lens wear is a common predisposing factor in microbial keratitis and is one of the two preventable risk factors for corneal infection in a working age population. Our understanding of the prevention and prophylaxis of contact lens-related corneal infection is informed by recent epidemiological studies describing the incidence of and risk factors for the disease, the effect of causative organism on disease severity, and an appreciation of individual immune profiles in susceptibility to and severity of the disease. Although contemporary contact lenses have not reduced the overall incidence of keratitis, a reduction in morbidity may be achievable through recognition of appropriate risk factors in severe disease, including avoiding delays in presenting for appropriate treatment, and attention to storage case hygiene practise. Severe keratitis is most commonly associated with an environmental causative organism, and daily disposable lenses are associated with less severe disease. Pseudomonas aeruginosa remains the commonest cause of contact lens-related corneal infection probably because of its unique virulence characteristics and ability to survive in the contact lens/storage case/ocular environment. In two recent outbreaks of contact lens-related infections, there has been a strong association demonstrated with particular contact lens solutions. Since the recall of these specific contact lens solutions, the rate of Acanthamoeba keratitis has remained above the expected baseline, indicating unidentified risk factors that may include environmental exposures. Individual differences in susceptibility to microbial keratitis may be partly explained by differences in single-nucleotide polymorphisms in certain cytokine genes, particularly those with a proven protective role in corneal infection. [ABSTRACT FROM AUTHOR]

Purpose: Contact lens behaviours such as poor hand and lens hygiene are common and are associated with increased risk of microbial keratitis. Evidence for health promotion strategies to address this gap is required. The trial examined the effectiveness of a customised text-messaging intervention on compliance, discontinuation rate and wearer satisfaction in contact lens wearers., Methods: The parallel group, double masked, randomised clinical trial was pre-registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12621001719820). Contact lens wearers were recruited using social media and optometry partners in clinical practice. Participants (n = 76) received the intervention and usual care. The control group (n = 75) received usual care. Intervention text messages (range 56-76) were customised, provided education, reminders, and motivation and were delivered over six months. Outcomes were validated self-report online surveys for compliance (0-100), satisfaction (0-100) and discontinuation (Y/N), at 3 months and 6 months. Secondary outcomes were intervention feasibility and acceptability., Results: Participants mean age was 38 years, 105/151 (70 %) female and 83 % completed the trial (intervention 60/76, control 65/75). The intervention group demonstrated better compliance than control with an adjusted between-group-difference at 3 months of 5.2, 95 % confidence interval (CI), 1.6-8.7, P = 0.004 and at 6 months 3.9, 95 % CI 0.2-7.6, P = 0.04. This difference in compliance is clinically significant, equivalent to a single change in a behaviour such as starting to handwash or ceasing overnight wear. There was no adjusted between-group-difference in satisfaction at 3 months (0.8, 95 % CI -4.3-6.0, P = 0.75) or at 6 months (-0.4, 95 % CI -5.7-4.9, P = 0.89). Few participants (7/151, 4.6 %) discontinued contact lens wear (3 intervention, 4 control). The messages were delivered successfully (98 %), at A$11 per participant. Participants reported appropriate message content (75 %), language (80 %) and delivery timing (97 %)., Conclusion: This customised text message intervention was a feasible and acceptable method for improving contact lens compliance., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: NC was awarded a UNSW Scientia Fellowship and AS was supported by a PhD Scientia Scholarship. This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. All authors attest that they meet the current ICMJE criteria for authorship. Authors AS, KF and LK indicate no financial disclosures or conflicts of interest. NC has previously received an educational grant from Alcon, honoraria from the British Contact lens Association (UK) and Optometry Virtually Connected, and travel grants from Standards Australia, and Australian Vision Convention (QLD/NT)., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

This paper seeks to outline the history, market situation, clinical management and product performance related to the correction of presbyopia with both contact lenses and spectacles. The history of the development of various optical forms of presbyopic correction are reviewed, and an overview is presented of the current market status of contact lenses and spectacles. Clinical considerations in the fitting and aftercare of presbyopic contact lens and spectacle lens wearers are presented, with general recommendations for best practice. Current options for contact lens correction of presbyopia include soft simultaneous, rigid translating and rigid simultaneous designs, in addition to monovision. Spectacle options include single vision lenses, bifocal lenses and a range of progressive addition lenses. The comparative performance of both contact lens and spectacle lens options is presented. With a significant proportion of the global population now being presbyopic, this overview is particularly timely and is designed to act as a guide for researchers, industry and eyecare practitioners alike., Competing Interests: Declaration of competing interest Philip B Morgan has received honoraria from Alcon, Bausch + Lomb, CooperVision, Menicon and Johnson & Johnson and grants/funding from Alcon, Bausch + Lomb, Clearlab, CooperVision, Daysoft, Johnson & Johnson Vision, Mark'Ennovy, Menicon and Visco Vision. Nathan Efron has received honoraria from CooperVision. Eric Papas has had grant funding from CooperVision and Alcon. Nicole Carnt has had funding from Alcon. Manbir Nagra provides consultancy to Menicon and Johnson & Johnson Vision. Helmer Schweizer provides consultancy to Alcon and Bausch + Lomb. Lakshman Subbaraman is an employee and has stock ownership of Alcon. Anna Sulley is an employee of CooperVision. At the time of writing this this paper Andy Hepworth is an employee of EssilorLuxottica. Melissa Barnett, Debarun Dutta, Julie-Anne Little, Heiko Pult, Bridgitte Shen Lee, Alicia Thompson, Alexandra Webster and Maria Markoulli have no declarations of competing interest., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Background: Microbial keratitis is one of the leading causes of blindness globally. An overactive immune response during an infection can exacerbate damage, causing corneal opacities and vision loss. This study aimed to identify the differentially expressed genes between corneal infection patients and healthy volunteers within the cornea and conjunctiva and elucidate the contributing pathways to these conditions' pathogenesis. Moreover, it compared the corneal and conjunctival transcriptomes in corneal-infected patients to cytokine levels in tears., Methods: Corneal and conjunctival swabs were collected from seven corneal infection patients and three healthy controls under topical anesthesia. RNA from seven corneal infection patients and three healthy volunteers were analyzed by RNA sequencing (RNA-Seq). Tear proteins were extracted from Schirmer strips via acetone precipitation from 38 cases of corneal infection and 14 healthy controls. The cytokines and chemokines IL-1β, IL-6, CXCL8 (IL-8), CX3CL1, IL-10, IL-12 (p70), IL-17A, and IL-23 were measured using an antibody bead assay., Results: A total of 512 genes were found to be differentially expressed in infected corneas compared to healthy corneas, with 508 being upregulated and four downregulated (fold-change (FC) <-2 or > 2 and adjusted p <0.01). For the conjunctiva, 477 were upregulated, and 3 were downregulated (FC <-3 or ≥ 3 and adjusted p <0.01). There was a significant overlap in cornea and conjunctiva gene expression in patients with corneal infections. The genes were predominantly associated with immune response, regulation of angiogenesis, and apoptotic signaling pathways. The most highly upregulated gene was CXCL8 (which codes for IL-8 protein). In patients with corneal infections, the concentration of IL-8 protein in tears was relatively higher in patients compared to healthy controls but did not show statistical significance., Conclusions: During corneal infection, many genes were upregulated, with most of them being associated with immune response, regulation of angiogenesis, and apoptotic signaling. The findings may facilitate the development of treatments for corneal infections that can dampen specific aspects of the immune response to reduce scarring and preserve sight., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Alenezi, Parnell, Schibeci, Ozkan, Willcox, White and Carnt.)

Acanthamoeba , a free-living amoeba in water and soil, is an emerging pathogen causing severe eye infection known as Acanthamoeba keratitis. In its natural environment, Acanthamoeba performs a dual function as an environmental heterotrophic predator and host for a range of microorganisms that resist digestion. Our objective was to characterize the intracellular microorganisms of phylogenetically distinct Acanthamoeba spp. isolated in Australia and India through directly sequencing 16S rRNA amplicons from the amoebae. The presence of intracellular bacteria was further confirmed by in situ hybridization and electron microscopy. Among the 51 isolates assessed, 41% harboured intracellular bacteria which were clustered into four major phyla: Pseudomonadota (previously known as Proteobacteria), Bacteroidota (previously known as Bacteroidetes), Actinomycetota (previously known as Actinobacteria), and Bacillota (previously known as Firmicutes). The linear discriminate analysis effect size analysis identified distinct microbial abundance patterns among the sample types; Pseudomonas species was abundant in Australian corneal isolates ( P  < 0.007), Enterobacteriales showed higher abundance in Indian corneal isolates ( P  < 0.017), and Bacteroidota was abundant in Australian water isolates ( P  < 0.019). The bacterial beta diversity of Acanthamoeba isolates from keratitis patients in India and Australia significantly differed ( P  < 0.05), while alpha diversity did not vary based on the country of origin or source of isolation ( P  > 0.05). More diverse intracellular bacteria were identified in water isolates as compared with clinical isolates. Confocal and electron microscopy confirmed the bacterial cells undergoing binary fission within the amoebal host, indicating the presence of viable bacteria. This study sheds light on the possibility of a sympatric lifestyle within Acanthamoeba , thereby emphasizing its crucial role as a bunker and carrier of potential human pathogens., Competing Interests: The authors have declared that no competing interests exist., (© The Author(s) 2024. Published by Oxford University Press on behalf of the International Society for Microbial Ecology.)

Background: Acanthamoeba is an environmental host for various microorganisms. Acanthamoeba is also becoming an increasingly important pathogen as a cause of keratitis. In Acanthamoeba keratitis (AK), coinfections involving pathogenic bacteria have been reported, potentially attributed to the carriage of microbes by Acanthamoeba. This study assessed the presence of intracellular bacteria in Acanthamoeba species recovered from domestic tap water and corneas of two different AK patients and examined the impact of naturally occurring intracellular bacteria within Acanthamoeba on the severity of corneal infections in rats., Methodology/principal Findings: Household water and corneal swabs were collected from AK patients. Acanthamoeba strains and genotypes were confirmed by sequencing. Acanthamoeba isolates were assessed for the presence of intracellular bacteria using sequencing, fluorescence in situ hybridization (FISH), and electron microscopy. The viability of the bacteria in Acanthamoeba was assessed by labelling with alkyne-functionalized D-alanine (alkDala). Primary human macrophages were used to compare the intracellular survival and replication of the endosymbiotic Pseudomonas aeruginosa and a wild type strain. Eyes of rats were challenged intrastromally with Acanthamoeba containing or devoid of P. aeruginosa and evaluated for the clinical response. Domestic water and corneal swabs were positive for Acanthamoeba. Both strains belonged to genotype T4F. One of the Acanthamoeba isolates harboured P. aeruginosa which was seen throughout the Acanthamoeba's cytoplasm. It was metabolically active and could be seen undergoing binary fission. This motile strain was able to replicate in macrophage to a greater degree than strain PAO1 (p<0.05). Inoculation of Acanthamoeba containing the intracellular P. aeruginosa in rats eyes resulted in a severe keratitis with increased neutrophil response. Acanthamoeba alone induced milder keratitis., Conclusions/significance: Our findings indicate the presence of live intracellular bacteria in Acanthamoeba can increase the severity of acute keratitis in vivo. As P. aeruginosa is a common cause of keratitis, this may indicate the potential for these intracellular bacteria in Acanthamoeba to lead to severe polymicrobial keratitis., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Rayamajhee et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Acanthamoeba is an opportunistic free-living heterotrophic protist that is the most predominant amoeba in diverse ecological habitats. Acanthamoeba causes amoebic keratitis (AK), a painful and potentially blinding corneal infection. Major risk factors for AK have been linked to non-optimal contact lens hygiene practices and Acanthamoeba contamination of domestic and recreational water. This study investigated the incidence and seasonal variation of Acanthamoeba spp. within coastal lagoons located on the eastern coast of Australia and then examined the association between Acanthamoeba and water abiotic factors and bacterial species within the water. Water samples were collected from four intermittently closed and open lagoons (ICOLLs) (Wamberal, Terrigal, Avoca and Cockrone) every month between August 2019 to July 2020 except March and April. qPCR was used to target the Acanthamoeba 18S rRNA gene, validated by Sanger sequencing. Water abiotic factors were measured in situ using a multiprobe metre and 16S rRNA sequencing (V3-V4) was performed to characterise bacterial community composition. Network analysis was used to gauge putative associations between Acanthamoeba incidence and bacterial amplicon sequence variants (ASVs). Among 206 water samples analysed, 79 (38.3%) were Acanthamoeba positive and Acanthamoeba level was significantly higher in summer compared with winter, spring, or autumn (p = 0.008). More than 50% (23/45) water samples of Terrigal were positive for Acanthamoeba which is a highly urbanised area with extensive recreational activities while about 32% (16/49) samples were positive from Cockrone that is the least impacted lagoon by urban development. All sequenced strains belonged to the pathogenic genotype T4 clade except two which were of genotype clades T2 and T5. Water turbidity, temperature, intl1 gene concentration, and dissolved O 2 were significantly associated with Acanthamoeba incidence (p < 0.05). The ASVs level of cyanobacteria, Pseudomonas spp., Candidatus spp., and marine bacteria of the Actinobacteria phylum and Acanthamoeba 18S rRNA genes were positively correlated (Pearson's r ≥ 0.14). The presence of Acanthamoeba spp. in all lagoons, except Wamberal, was associated with significant differences in the composition of bacterial communities (beta diversity). The results of this study suggest that coastal lagoons, particularly those in urbanised regions with extensive water recreational activities, may pose an elevated risk to human health due to the relatively high incidence of pathogenic Acanthamoeba in the summer. These findings underscore the importance of educating the public about the rare yet devastating impact of AK on vision and quality of life, highlighting the need for collaborative efforts between public health officials and educators to promote awareness and preventive measures, especially focusing lagoons residents and travellers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The healthy human cornea is a uniquely transparent sensory tissue where immune responses are tightly controlled to preserve vision. The cornea contains immune cells that are widely presumed to be intraepithelial dendritic cells (DCs). Corneal immune cells have diverse cellular morphologies and morphological alterations are used as a marker of inflammation and injury. Based on our imaging of corneal T cells in mice, we hypothesized that many human corneal immune cells commonly defined as DCs are intraepithelial lymphocytes (IELs). To investigate this, we developed functional in vivo confocal microscopy (Fun-IVCM) to investigate cell dynamics in the human corneal epithelium and stroma. We show that many immune cells resident in the healthy human cornea are T cells. These corneal IELs are characterized by rapid, persistent motility and interact with corneal DCs and sensory nerves. Imaging deeper into the corneal stroma, we show that crawling macrophages and rare motile T cells patrol the tissue. Furthermore, we identify altered immune cell behaviors in response to short-term contact lens wear (acute inflammatory stimulus), as well as in individuals with allergy (chronic inflammatory stimulus) that was modulated by therapeutic intervention. These findings redefine current understanding of immune cell subsets in the human cornea and reveal how resident corneal immune cells respond and adapt to chronic and acute stimuli.

Objective: The study aimed to profile and quantify tear metabolites associated with bacterial keratitis using both untargeted and targeted metabolomic platforms., Methods: Untargeted metabolomic analysis using liquid-chromatography-Q Exactive-HF mass-spectrometry explored tear metabolites significantly associated with bacterial keratitis (n = 6) compared to healthy participants (n = 6). Differential statistics and principal component analysis determined meaningful metabolite differences between cases and controls. Purines and nucleosides were further quantified and compared between 15 cases and 15 controls in the targeted metabolomic platform using TSQ quantum access triple quadrupole mass spectrometry. Compound quantification was done by plotting the calibration curves and the difference in the compound levels was evaluated using the Wilcoxon rank-sum test., Results: In the untargeted analysis, 49 tear metabolites (27 upregulated and 22 downregulated) were differentially expressed between cases and controls. The untargeted analysis indicated that the purine metabolism pathway was the most affected by bacterial keratitis. Metabolite quantification in the targeted analysis further confirmed the upregulation of xanthine (P = 0.02) and downregulation of adenine (P < 0.0001), adenosine (P < 0.0001) and cytidine (P < 0.0001) in the tears of participants with bacterial keratitis compared to that of healthy participants., Conclusions: Bacterial keratitis significantly changes the tear metabolite profile, including five major compound classes such as indoles, amino acids, nucleosides, carbohydrates, and steroids. This study also indicates that tear fluids can be used to map the metabolic pathways and uncover metabolic markers associated with bacterial keratitis. Conceivably, the inhibition of nucleoside synthesis may contribute to the pathophysiology of bacterial keratitis because nucleosides are required for maintaining cellular energy homeostasis and immune adaptability., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Purpose: This study was designed to establish risk factors for the development of Acanthamoeba keratitis (AK) for daily disposable (DD) contact lens (CL) users compared with daily wear (DW) reusable lens users and for risks unique to DD users. This is important because, in many major economies, CL use is the principal cause of microbial keratitis, of which AK accounts for approximately 50% of cases with sight loss. Determining these AK risks informs practitioner advice and consumer behavior., Design: Case-control study., Participants: Cases and controls were recruited from an Accident and Emergency Department serving South-East England. Cases were new CL users with AK recruited retrospectively from January 2011 to February 2013 and prospectively thereafter until August 2014. Controls were recruited prospectively from February 2014 to June 2015., Methods: Analysis of a self-administered questionnaire., Main Outcome Measures: Independent risk factors and population attributable risk percentage (PAR%) for AK., Results: A total of 83 AK cases and 122 controls were recruited; DD use was reported by 20 (24%) cases and 66 (54%) controls. In multivariable analyses adjusted for potential confounders, the odds of AK was higher for DW reusable soft lenses (odds ratio [OR], 3.84; 95% confidence interval [CI], 1.75-8.43) and rigid lenses (OR, 4.56; 95% CI, 1.03-20.19) than for DD lenses. Within the DD-using subset, AK was associated with the following modifiable risk factors: less frequent professional follow-up visits (OR, 10.12; 95% CI, 5.01-20.46); showering in lenses (OR, 3.29, 95% CI, 1.17-9.23); lens reuse (OR, 5.41; 95% CI, 1.55-18.89); and overnight wear (OR, 3.93; 95% CI, 1.15-13.46). The PAR% estimated that 30% to 62% of cases could be prevented by switching from reusable soft lens to DD lens use., Conclusions: Acanthamoeba keratitis risks are increased > threefold in DW reusable lens users versus DD lens use. Acanthamoeba keratitis risks for DD lens users can be minimized by adherence to safe use guidelines (no reuse, overnight wear, or contamination by water). Safe CL use can be improved by increasing the prominence of risk avoidance information from manufacturers and regulators. Because AK accounts for half of severe keratitis in CL users, these measures can be expected to have public health benefits., (Copyright © 2022 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Aims: To evaluate the sensitivity and specificity of polymerase chain reaction (PCR), in vivo confocal microscopy (IVCM) and culture for microbial keratitis (MK) diagnosis., Methods: Retrospective review of PCR, IVCM and culture results for MK diagnosis at Moorfields Eye Hospital between August 2013 and December 2014., Results: PCR results were available for 259 MK patients with concurrent culture for 203/259 and IVCM for 149/259. Sensitivities and specificities with 95% confidence intervals [95% CI] were calculated for Acanthamoeba keratitis (AK) and fungal keratitis (FK), by comparison with culture, for both IVCM and PCR. For AK, FK and bacterial keratitis (BK) sensitivities were calculated, for each diagnostic method, by comparison with a composite reference standard (a positive result for one or more of culture, PCR or IVCM having a specificity of 100% by definition). For the latter, sensitivities with [95% CI] were: for AK, IVCM 77.1% [62.7-88.0%], PCR 63.3% [48.3-76.6%], culture 35.6 [21.9-51.2]; for FK, IVCM 81.8% [48.2-97.7%], PCR 30.8% [9.09-61.4%], culture 41.7% [15.2-72.3%]; for BK, PCR 25.0% [14.7-37.9%], culture 95.6% [87.6-99.1%]., Conclusion: IVCM was the most sensitive technique for AK and FK diagnosis but culture remains our gold standard for BK. These findings reflect results to be expected from service providers to UK ophthalmology units and demonstrates the need at our centre for ongoing diagnostic result audit leading to the potential to improve PCR diagnosis. Both FK and AK are now common in the UK; ophthalmology units need to have all these techniques available to optimise their MK management., (© 2021. The Author(s).)

The opportunistic protist Acanthamoeba, which interacts with other microbes such as bacteria, fungi, and viruses, shows significant similarity in cellular and functional aspects to human macrophages. Intracellular survival of microbes in this microbivorous amoebal host may be a crucial step for initiation of infection in higher eukaryotic cells. Therefore, Acanthamoeba-microbe adaptations are considered an evolutionary model of macrophage-pathogen interactions. This paper reviews Acanthamoeba as an emerging human pathogen and different ecological interactions between Acanthamoeba and microbes that may serve as environmental training grounds and a genetic melting pot for the evolution, persistence, and transmission of potential human pathogens., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Introduction: Acanthamoeba is an emerging pathogen, infamous for its resilience against antiprotozoal compounds, disinfectants and harsh environments. It is known to cause keratitis, a sight-threatening, painful and difficult to treat corneal infection which is often reported among contact lens wearers and patients with ocular trauma. Acanthamoeba comprises over 24 species and currently 23 genotypes (T1-T23) have been identified., Aims: This retrospective study was designed to examine the Acanthamoeba species and genotypes recovered from patients with Acanthamoeba keratitis (AK), determine the presence of endosymbionts in ocular isolates of Acanthamoeba and review the clinical presentations., Methodology: Thirteen culture-confirmed AK patients treated in a tertiary eye care facility in Hyderabad, India from February to October 2020 were included in this study. The clinical manifestations, medications and visual outcomes of all patients were obtained from medical records. The Acanthamoeba isolates were identified by sequencing the ribosomal nuclear subunit (rns) gene. Acanthamoeba isolates were assessed for the presence of bacterial or fungal endosymbionts using molecular assays, PCR and fluorescence in situ hybridization (FISH)., Results: The mean age of the patients was 33 years (SD ± 17.4; 95% CI 22.5 to 43.5 years). Six (46.2%) cases had AK associated risk factors; four patients had ocular trauma and two were contact lens wearers. A. culbertsoni (6/13, 46.2%) was the most common species, followed by A. polyphaga and A. triangularis. Most of the isolates (12/13) belonged to genotype T4 and one was a T12; three sub-clusters T4A, T4B, and T4F were identified within the T4 genotype. There was no significant association between Acanthamoeba types and clinical outcomes. Eight (61.5%) isolates harboured intracellular bacteria and one contained Malassezia restricta. The presence of intracellular microbes was associated with a higher proportion of stromal infiltrates (88.9%, 8/9), epithelial defect (55.6%, 5/9) and hypopyon (55.6%, 5/9) compared to 50% (2/4), 25% (1/4) and 25% (1/4) AK cases without intracellular microbes, respectively., Conclusions: Genotype T4 was the predominant isolate in southern India. This is the second report of T12 genotype identified from AK patient in India, which is rarely reported worldwide. The majority of the Acanthamoeba clinical isolates in this study harboured intracellular microbes, which may impact clinical characteristics of AK., (© 2022. The Author(s).)

Purpose: To determine if there is diurnal variation in gene expression in normal healthy conjunctival cells., Methods: Bulbar conjunctival swab samples were collected from four healthy subjects in the morning and evening of the same day. The two swab samples were taken from one eye of each participant, with a minimum of five hours gap between the two samples. RNA was extracted and analysed using RNA sequencing (RNA-Seq)., Results: A total of 121 genes were differentially expressed between the morning and the evening conjunctival samples, of which 94 genes were upregulated in the morning, and 27 genes were upregulated in the evening. Many of the genes that were upregulated in the morning were involved in defence, cell turnover and regulation of gene expression, while the genes upregulated in the evening were involved in signalling and mucin production., Conclusions: This study has identified several genes whose expression changes over the course of the day. Knowledge of diurnal variations of conjunctival gene expression provides an insight into the regulatory status of the healthy eye and provides a baseline for examining changes during ocular surface disease., (Copyright © 2021 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Glaucoma is a chronic optic neuropathy that creates a significant burden on public health. Oxidative stress is hypothesized to play a role to glaucoma progression, and its reduction is being analyzed as a therapeutic target. Dietary antioxidants play a crucial role in helping provide insight into this hypothesis. We reviewed 71 trials, interventional, in-vivo and Iin vitro, including 11 randomized controlled trials, to determine if adjunctive nutritional supplementation could lead to a reduction in oxidative stress and prevent glaucomatous progression. Many laboratory findings show that vitamins and natural compounds contain an abundance of intrinsic antioxidative, neuroprotective and vasoprotective properties that show promise in the treatment and prevention of glaucoma. Although there is encouraging early evidence, most clinical findings are inconclusive. The group of B vitamins appear to have the greatest amount of evidence. Other compounds such as flavonoids, carotenoids, curcumin, saffron, CoQ10, gingko biloba, and resveratrol however warrant further investigation in glaucoma patients. Studies of these antioxidants and other nutrients could create adjunctive or alternative preventative and treatment modalities for glaucoma to those currently available., Competing Interests: Declaration of Competing Interest The authors of this paper have no conflicts of interest to declare., (Crown Copyright © 2021. Published by Elsevier Inc. All rights reserved.)

Acanthamoeba keratitis (AK) is a rare but severe eye disease. A research engagement event, "The Cornea Day," in London, UK in 2013, identified the lack of credible information about AK and a need for practical day to day management strategies. Experiences of 15 AK patients attending The Cornea Day were distilled into a survey that was administered to a wider group of 76 patients, carers, researchers, and clinicians. A Patient Information Leaflet was cocreated and then represented to additional patients for final modification. The AK Patient Leaflet (revised 2019) is available in several languages and used globally., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2022.)

Mucosal linings of the body, including the conjunctiva, are enriched in tissue-resident memory T cells (T RMs ) whose defining feature is their continual tissue protection that does not rely on migration to lymphoid organs to elicit immune responses. Hitherto, conjunctival T RMs have only been identified in the superficial epithelium. This work aims to develop a more complete understanding of the conjunctival immunological capacity by investigating the presence of T RMs within the deeper, more stable layers of the healthy human conjunctiva. Using immunofluorescence microscopy and antibodies against CD3, CD4, CD69 and HLA-DR on bulbar conjunctival biopsies obtained from 7 healthy adults (age range = 32-77 years; females = 4), we identified CD69 + T RM subsets in all layers of the human conjunctiva: the superficial epithelium, the basal epithelium, the adenoid, and the fibrous layers. Interestingly, the adenoid layer showed significantly higher densities of both CD4 and CD8 T RMs when compared to the fibrous layer and conjunctival epithelia. Additionally, CD4 T RMs predominated significantly over CD8 T RMs in the adenoid layer. The abundance of deep conjunctival CD69 + T RMs within the healthy human may suggest the presence of defence mechanisms capable of inducing long-term immunogenic memory. Understanding this spatial distribution of conjunctival CD69 + T RMs is essential to improving mucosal vaccine design., (© 2022. The Author(s).)

Abstract: Infectious keratitis is a rare but severe condition associated with a range of ocular and systemic predisposing conditions, including ocular trauma, prior surgery, surface disease, and contact lens (CL) wear. This review explores the epidemiology of infectious keratitis, specifically the differences in disease incidence and risk factors, causative organism profile and virulence characteristics and host microbiome, genetics, gene expression, proteomics, and metabolomic characteristics in CL-related and non-CL-related diseases. Differences exist in the epidemiology, demographics, causative organisms, and their virulence characteristics in CL-related and non-CL-related diseases, and there is less evidence to support differences between these groups of individuals in the ocular surface microbiome, genetics, and pathways of disease. Genetic variations, however, in the host immune profile are implicated in both the onset and severity of infectious keratitis in CL and non-CL wearers. As technologies in metabolomics, proteomics, and genomics improved to be better able to process small-volume samples from the ocular surface, there will be improved understanding of the interplay between the CL, ocular surface, host immune profile, and the microbial environment. This may result in a more personalized approach in the management of disease to reduce disease severity., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2022 Contact Lens Association of Ophthalmologists.)

The COVID-19 pandemic has resulted in an unprecedented impact on global health, economy, and way of life. SARS-CoV-2, the virus responsible for the disease, utilizes the ACE2 receptor found on host cells to mediate entry, replication, and infection. Numerous studies have elucidated the presence of many components of the renin-angiotensin-aldosterone system (RAAS) in the eye, including the ACE2 receptor. Considering this, and the anatomical vulnerability that the exposed ocular surface offers with its interconnectedness to the respiratory system, there is a theoretical risk of pathogen entry from the ocular route as well as the development of COVID-19-associated eye disease. Despite this, the actual epidemiological data demonstrates low ocular symptoms, possibly due to differing ACE2 receptor expression across age, ethnicity, and sex coupled with the protective properties of tears. We summarize the current literature on ocular RAAS with specific focus on the ACE2 receptor and its interplay with the SARS-CoV-2 virus., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this article., (Copyright © 2022 Ali Abid et al.)